UNI-T UT285C Power Quality Analyzer User Manual

June 5, 2024
UNI-T

UNI T logo

UT285C
UNI T UT285C Power Quality Analyzer
P/N:110401110254X 2021/07/06 REV.0

Power Quality Analyzer
Operating  Manual

UT285C Power Quality Analyzer

Warning
Thank you for purchasing our UT285C Power Quality Analyzer, in order to better use this product, be sure to:
–To read this user manual in detail.
–To abide by the safety regulations and precautions strictly.

  • Failure to comply with these precautions may result in an electric shock, explosion, or fire.
  • Under any circumstance, it shall pay special attention to the safety of the use of this device.
  • Pay attention to words and symbols that stick on the panel and back of the device.
  • This measuring device is only to be used, disassembled, and repaired by qualified personnel with authorization.
  • When it may cause a hazard by continuous use for the reason of the device itself, it shall immediately stop using it and deposit it at once, leaving it for disposal by an authorized agency.
  • For the risk of danger icon in the manual “ ****“, users must perform safe operations strictly in compliance with the manual content.
  • The user must strictly follow the instructions preceded by “  “the danger symbol on the instrument and manual.
  • When removing and replacing the battery and/or the SD Card, make sure that the device is disconnected and off.
  • The current clamp must be correspondingly connected with the device, if not the test error may increase.
  • The device must not be used if the “battery/SD Card” compartment cover is missing, damaged, or incorrectly fitted.
  • The safety of any system incorporating this instrument is the responsibility of the system assembler.
  • For your safety, use only the compatible leads and accessories delivered with the instrument, which comply with IEC standard 61010-031 (2002). When sensors or accessories having a lower voltage rating and/or category are connected to the instrument, the lower voltage and/or category applies to the system so constituted.
  • Before use, check that the leads, enclosures, and accessories are in perfect condition. Any lead, sensor, or accessory of which the insulation is damaged (even partially) must be repaired or scrapped.
  • Comply with the environmental conditions (see 15.3.1)
  • We recommend using Personal Protection Equipment where required.
  • This device may be used on category IV installations for voltages that do not exceed 600 V (AC or DC) with respect to earth (as per IEC standard 61010-1), or on category III installations for voltages that do not exceed 1000 V. Never use it on networks of which the voltage or category exceeds those mentioned.
  • Use only the mains power adaptor and battery pack supplied by the manufacturer. They include specific safety features.
  • Do not reach past the physical guards on the accessories and sensors. Keep your hands away from unused terminals.
  • Some current sensors must not be placed on or removed from bare conductors at hazardous voltage.

Connection procedure:

  • Switch the instrument on.
  • Configure the device for the measurement to be made and the type of network concerned.
  • Connect the leads and current sensors to the unit.
  • Connect the earth and/or neutral lead to the network earth and/or neutral and connect the corresponding current sensor.
  • Connect the L1 phase lead to the network L1 phase and connect the corresponding current sensor. If applicable, repeat the procedure for phases L2, and L3.
    Note: complying with this procedure reduces connection errors to a minimum and avoids wasting time.

Disconnection procedures:

  • Proceed in the reverse of the order of connection, always finishing by disconnecting the neutral (when distributed). Disconnect the leads and switch the device off.
  • Charging the battery and uploading the test data when necessary.
    USB is used for data transmission, the battery can be charged by the fringe special adapter.

Homonymous ends of the current clamp

  • The side of the current clamp marks L1, L2, L3, N/D or has a red dot is the current noninverting input, that is the homonymous end.
  • The side of 008B current clamp has a red dot is the current noninverting input, which is the homonymous end.
  • The side of 040B, 068B current clamp without screws is the current noninverting input, which is the homonymous end.

SUMMARY

1.1. Introduction

UT285C Power Quality Analyzer is a comprehensive test instrument carefully developed by our company and specially designed for field tests of three phases, multi-functional and intelligent, concise man-machine operation. It is easy to use, large LCD screen display, high resolution, interface in both Chinese and English, shock-proof shell structure, and so on. Can simultaneously measure the 4-channel current (ABC three-phase and neutral wire current), 4-channel voltage (ABC three-phase voltage and neutral line voltage to ground), the peak value of current voltage, maximum/minimum value over a period, three-phase imbalance factor, short-time voltage flicker, transformer K factor, active power, reactive power, apparent power, power factor and displacement power factor, active power, reactive power, apparent power, total harmonic distortion and harmonic, etc; Display real-time waveform, harmonic ratio bar charts of current-voltage; Dynamically capture the instantaneous change of voltage current, monitoring starting current, monitoring the power parameters and generate the alarm list, generate the trend chart for a long time record test data.
In the current power applications, more and more large power equipment, and power grid fault have become more and more complex, with the development of the industry, it put forward high requests for more and more quality than electric energy. We provide this power quality analyzer for that, which you can troubleshoot complex power systems more quickly and accurately, and monitor and maintenance of power quality parameters more comprehensively and systemic.
UT285C Power quality analyzer adopts DSP + ARM double processor architecture, DSP is used for data collection and the processing of algorithm, the ARM is used for the communication protocol and the man-machine interface processing; Analog signal acquisition is by 2 pieces AD7655 of ADI company. The resolution for AD7655 is 16 bit and it is 4-channel synchronous sampling. The highest sampling rate can reach 1 MSPS, to ensure the accuracy of the channel and the information integrity, and wouldn’t miss any transient changes in the grid, can be more accurate to detect the transient waveform rising and dropping drastically, and waveform instantaneous interrupt; DSP working frequency is over 200 MHZ, to be able to timely monitoring of the power grid and dynamically adjust the sampling frequency to realize synchronization of power frequency and sampling frequency; Using a 5.6 -inch LCD color screen display, a resolution of 640 dots x 480 dots, with different display color difference between the parameters of phase, waveform, vector diagram, harmonic ratio, the user can be more efficient and more intuitive understand the state of power grid parameters. Built-in flash memory can store 60 groups of screenshots at the same time, 150 groups of capture transient voltage/current waveform figures, and 12800 groups of alarm lists. Starting current detection model can continuously capture starting current waveform for 100 s. Built-in 2G memory card to store the trend curve record, simultaneously recording 20 parameters (can choose according to to need) collect data once every five seconds, trend curve records can be stored for 300 days.
Power Quality Analyzer also named: Intelligent Three Phase Power Quality Analyzer, Multifunctional Power Quality Analyzer, which is simultaneous with the functions of harmonic Analyzer, phase volt-ampere meter, and electric parameter tester. It applies to the electricity industry, petrochemical, metallurgy, railway, mining enterprises, scientific research institution, and metrological departments. Especially suitable for comprehensive analysis and diagnosis of all the voltage, current, power, power, harmonic, and phase electric parameters.

1.2. Function
1.2.1. Basic function

Waveform real-time display (4 channels voltage/4 channels current).

  • True RMS values of voltages and currents.
  • The DC components of voltages.
  • Peak current and voltage values.
  • Minimum and maximum half-cycle RMS current and voltage values.
  • Pharos diagram display.
  • Measurement of each harmonic up to order 50.
  • Bar charts show harmonic ratios of the current and voltage of each phase.
  • Total harmonic distortion (THD).
  • Active, reactive, apparent power, by phase, and cumulative.
  • Active, reactive, apparent energy, by phase, and cumulative.
  • Transformer K factor.
  • Power factors (PF) and displacement factors (PDF or COS).
  • Short-term voltage flicker (PST).
  • Three-phase unbalance(current and voltage).

1.2.2. Capture function

  • Transient capture function
    Monitoring instantaneous change of power grid voltage current parameters, including the voltage current fluctuations, voltage current surge, sag and short supply interruption, temporary overvoltage, impact current, and Current- voltage instantaneous distortion. Instruments can store 150 sets of transient waveforms at the same time.

  • Starting current monitoring
    Monitoring the surge current of the line and the startup current when electrical equipment is starting helps to correctly design capacity. Can display the RMS rising/falling curve In the startup process, the envelope curve of startup current, the waveform of 4 channels current and 4 channels voltage. Recording about 100s after the trigger, storage of the current /voltage instantaneous, and waveform curve of each cycle in 100s.

  • Trend chart recording and storing function
    Store all the test parameters of basic test functions (Urms, Utd, Ucf, Uunb, Hz, Vrms, Vthd, Vcf, Vunb, PST, Arms, Athd, Acf, Aunb, KF, W, VAR, VA, PF, COS, TAN),50 voltage harmonics, 50 current harmonics. And create the trend curve. Record data for a long time according to need(concurrent selection of 20 parameters to record data once every five seconds, you can record about 300 days.).

  • Alarm function
    Set the limit values according to need, monitoring the values whether overshoot, if overshoot will generate an alarm log, such as voltage, current, unbalance, harmonic ratio, frequency, active power, and total harmonic distortion. You can configure 40 different alarms, each group can set different monitoring parameters (including 50 harmonics, a total of 123 different parameters) and limit values, and also can set the shortest time of overshoot. The log can contain up to 12,800 alarms.

  • Snapshot function
    Any screen can be saved (screen snapshot), at the same time automatically recording the time and test mode. Such as can save voltage and current waveform, harmonic bar charts, phasor diagrams, etc. It can save a maximum of 60 screen snapshots.

1.2.3. Other functions

  • Communication function
    Communicate with computer via USB; Monitoring software can display the waveform of the power quality analyzer, read the transient waveform, trend chart recording, alarm log, screenshots, and display on the computer.

  • Setting function
    The user can configuration of the time and date, configuration of the screen contrast and brightness, definition of each phase curve color’.
    Choice of type of connection to the network. Configuration of the type of current sensors and voltage ratios. Select the Chinese menu or English menu. Help menu in Chinese/English Every stage of operation can press the “help” key to obtain relevant information.

1.3. Technical specification
1.3.1. Base condition and working condition

Influence factor Test item Base condition Working condition
Environment temperature All parameters (23±2)°C -10°C— 40°C
Relative humidity All parameters 40%’ 60% <80%
Phase-to-neutral voltage All parameters (100±1%)V 1.0V— 1000V
phase-to-phase voltage True RMS phase-to-phase voltage (200±1%)V 1.0V—

2000V
Current| True RMS current| (5±1%)A| 10mA— 1000A
Network frequency| All parameters| 50Hz±0.1Hz| 40Hz— 70Hz
Phase shift| Active power and active energy| Cos4=1| Cosh: 0.2— 1.0
Reactive power and reactive energy| Sin4=1| Sin.: 0.2— 1.0
Harmonic| All parameters| <0.1%| 0.0%— 100%
Voltage unbalance| All parameters| <10%| 0.0%— 100%
The working voltage of the device| All parameters| DC9.8V±0.1V| DC9.5V— 10.5V
External electric field, magnetic field| All parameters| Should be avoided
Test position| Measured related parameters of the current| Tested wire at the center of clamp.

1.3.2. General specification

Power supply Rechargeable lithium-ion battery packs 9.6V, backup charger.
Battery indicator The battery symbol shows dump energy. When the voltage is

too low, automatic shutdown after 1 minute.
Power consumption| Current consumption of normal test 490 mA, continuous working for 8 hours.
Display mode| LCD color screen, 640dotsx480dots, 5.6 inches, display domain: 116mmx88mm.
---|---
Size of clamp| 068B circle current clamp: 68mmx68mm.
Instrument dimensions| LxWxH: 240m mx170mmx68 mm.
Number of channels| 4u/41.
Phase-to phase voltage| 1.0V-2000V.
Phase-to-neutral voltage| 1.0V-1000V.
Current| 068B current clamp: 1.0A-1000A;
Frequency| 40Hz-70Hz.
Parameters of electricity| W, VA, Var, PF, DPF, cos4, tan4.
Energy parameters| Wh, Varh, Vah.
Harmonic| Order 0-50.
Total harmonic distortion| Order 0-50, for each phase.
Expert mode| Yes.
Number of Transient records| 150 sets.
Voltage flicker| Yes.
Starting current mode| Yes, 100 seconds.
3 phases unbalance| Yes.
Record| 300 days(simultaneous recording 20 parameters, recording one point every 5 seconds).
Min/Max recorded value| Measurement of maximum and minimum values over a period of time.
Alarm| 40 different types of parameter selections, and 12,800 sets of alarm logs.
Peak| Yes.
Phasor diagram display| Automatically.
Capacity of snapshots| 60.
Menu language| English/Chinese.
Communication| USB.
| When an alarming campaign is initiated or a search for transients, an inrush current
Automatic switching off| a capture or a trend recording is pending or in progress, the device is not automatically switching off.
---|---
In another test mode, 15 minutes without keystrokes, automatic shutdown after prompt 1 minute.
Backlight function| Yes, suitable for use at night and in dark places.
Weight| Host: 1.6kg (with battery).
068B circle current clamp: 510gx4;
Test wires and power adapter: 900g;
Length of voltage test wire| 3m.
Length of current sensor wire| 2m.
Working temperature and humidity| -10°C-40°C; below 80%Rh.
Storage temperature and humidity| -10°C-60°C; below 70%Rh.
Input impedance| The input impedance of test voltage: 1Mi1.
Withstand voltage| Withstand 3700V/SOHz sinusoidal AC voltage for 1 minute between instrument wiring and shell.
Insulation| Between instrument wiring and shell nOMO.
Structure| Double insulation, with insulation vibration-proof sheath.
Safely rules| IEC 61010 1000V Cat III / 600V CAT IV, IEC61010-031, IEC61326, Pollution degree: 2.

1.3.3. Instrument precision (excluding the current sensor)
Respectively introduce the following data (on the basis of base conditions and the ideal current sensors, perfectly linear, no phase shift)

Measurement| Range| Display resolution| The maximum error in the range of the
reference
---|---|---|---
Frequency| 40Hz- 70Hz| 0.01Hz| t(0.03)Hz
True RMS phase-to-neutral voltage| 1.0r 1000V| Min resolution 0.1V| ±(0.5%+Sclgt)
True RMS phase-to-phase voltage| 1.0V– 2000V| Min resolution 0.1V| ±(0.5%+5dgt)
---|---|---|---
DC voltage| 1.0r 1000V| Min resolution 0.1V| ±(1.0%+5dgt)
True RMS current| 10mA– 1000A| Min resolution lmA| ±(0.5%-E5dgt)
Peak of phase-to-neutral voltage| 1.0r 1414V| Min resolution 0.1V| ±(1.0%+5dgt)
Peak of phase-to-phase
voltage current peak Peak factor| 1.0r 2828V
10mA– 1414A
1.00– 3.99| Min resolution 0.1V
Min resolution lmA
0.01| ±(1.0%-F5dgt)
±(1.0%+Sclgt)
±(1%-E2dgt)
4.00`9.99| 0.01| ±(5%+2dgt)
Active power| 0.000W– 9999.9kW| Min resolution 0.001W| ±(1%+3dgt)
Cos00.8
t(1.5%+10dgt)
0.25Cos4≥0.8
Reactive power,

inductive or capacitive

Apparent power

Power factor

| 0.000VAR–

9999.9 kVAR

0 .000VA–

9999.9kVA

-1.000– 1.000

| Min resolution 0.001VAR

Min resolution 0.001VA

0.001

| ±(1%+3dgt)
Sing)≥0.5
±(1.5%+10dgt)
0.25Sing≥0.5
±(1%+3dgt)
±(1.5%+3dgt)
Cos00.S
±(1.5%+10dgt)
0.2≤Cos∅∠0.5
Active energy| 0.000Wh– 9999.9MWh| Min resolution 0.001Wh| ±(1%+3dgt)
| | | Coscka0.8
---|---|---|---
±(1.5%+10dgt)
0.25Cos4i<0.8
Reactive energy, inductive or capacitive

Apparent energy

| 0.000VARh— 9999.9MVARh| Min resolution
0.001VARh
Min resolution 0.001VAh| ±(1%+3dgt)
Sincka0.5
±(1.5%+10dgt)
|0.25Sin4′<0.
±(1%+3dgt)
0.000VAh– 9999.9MVAh
Phase angle
Tan, (VAa5OVA)| -179°— 180°
-32.76— 32.76| 1°
Min resolution 0.001| ±(2°)
1):±(1°)
The phase shift of the power factor
(PDF)| -1.000— 1.000| 0.001| 1):±(1°)
Harmonic ratio
(order 1 to 50) (Vrms>50V)Harmonic angle
(Vrms>50V)| 0.0%— 99.9%

-179°— 180°

| 0.1%

| ±(1%+5dgt)

±(3°) harmonics of order 1 to 25
±(10°) harmonics of order 26 to 50

Total harmonic ratio
(THD or THD-F)550
Distortion factor
(DF or THD-R)550
Transformer K factor
3 phases unbalance| 0.0%— 99.9%
0.0%— 99.9%
1.00— 99.99
0.0%— 100%| 0.1%
0.1%
0.01
0.1%| ±(1%+5dgt)
±(1%+10dgt)
±(5%)
±(1%)
Type of current sensor| True RMS current| current| Max error of phase angleφ
---|---|---|---
068B current clamp| 1.0A~ 9.9A| ±(2%+3dgt)| ±(3°)
10.0A~ 1000A| ±(2%+3dgt)| ±(2°)

Note: current clamp and instruments must be connected to the corresponding, and cannot be inserted opposite.
★ The side of the current clamp marks L1, L2, L3, N/D or has a red dot is the current noninverting input, that is the homonymous end.
★ The side of 040B, 068B current clamp without screws is the current noninverting input, that is homonymous end

PACKING

2.1. Standard configuration

No. Designation Quantity
1 Instrument host. 1
2 Instrument knapsack. 1
3 Current sensors 4
5 Testing wires. 5 (yellow, green, red, blue, black)
6 Crocodile clips. 5
7 Test probe. 5
8 Dedicated power adapter. 1
9 USB data cord. 1
10 Software CD. 1
11 Lithium battery pack. 1 (Built into the instrument)
12 2GB memory. 1 (Plug in the instrument)
13 Manual, warranty card, certification. 1

2.2. Weight

No. Designation Weight
1 Instrument host. 1.6Kg (with battery).
2 068B circle current clamp. 510g×4.
3 Test wires and power adapter. 900g.

PRESENTATION

3.1. Overall view

UNI T UT285C Power Quality Analyzer - Overall view

3.2. On/Off key
Pressing starts the device.
The device can be powered by the battery alone (if it is adequately charged) or by a specific mains power supply unit(if, in this case, the battery is also present, the power supply unit charge it).
Pressing the key again turns the device off. Confirmation is required to turn it off if the device is in one of its recording modes or is searching for transients, alarm, and/or inrush current capture.
3.3. Display screen
3.3.1. Presentation
This backlit 640×480 pixel graphic liquid crystal screen displays all measurements with their curves, the parameters of the unit, the curves selected, the instantaneous values of the signals, and the type of measurement selected When the device is powered up, it automatically displays the Waveform screen. Information about this screen can be found in §8.UNI T UT285C Power
Quality Analyzer - Overall view1

Automatic switching off:
When an alarming campaign is initiated or a search for transients, an inrush current capture, or a trend recording is pending or in progress, the device is not automatically switched off. In another test mode, 15 minutes without keystrokes, automatic switching off after prompt 1 minute.
3.3.2. Icons
The display uses the following icons

Icon Designation Icons Designation
V Phase-to-neutral voltage. Display of voltage and current RMS values and

their extrema
U| Phase-to-phase voltage.| | Simultaneous display of all voltage and current measurements
A| Current.| | Display of voltage and current vector diagram.
VA| Apparent power.| | Energies consumed.
| Zoom in.| | Energies generated.
| Zoom out.| | Page screen 1 of the help function.
▼| The X-axis cursor indicator.| | Page screen 2 of the help function.
PF…| Display of PF, PDF, Tanφ.| | Page screen 3 of the help function.
W…| Display of powers and energies values.| | The monitoring parameter of group 1 is in the trend mode.
| Start Record.| | The monitoring parameter of group 2 in the trend
---|---|---|---
| Recording list.| | The monitoring parameter of group 3 in the trend
OK| Validation prompt.| | The monitoring parameter of group 4 in the trend
| Shut down.| | Previous page screen.
| Delete.| | Next page screen.

3.4. Keypad keys
3.4.1. Function keys(yellow keys)
These 6 keys activate the function or tool represented by the corresponding icon on the screen.
3.4.2. Navigation keys
A block of 4 arrow keys, a confirm key, and a return key are used for navigation in the menus

Item Function
Up direction or zoom in key.
Down the direction or zoom out the key.
Right direction or next page key.
Left direction or previous page key.
Confirms the selection.
Return key.

3.4.3. Mode keys
These give access to specific modes

Item Function Voir
Waveform mode: the display of voltage and current waveforms, maxima and
minima, extreme value, summary tables, voltage, and current vector diagrams

8
| Harmonic mode: the display of voltage, current, and apparent power harmonic ratios (displayed in a graph), harmonic RMS value, and phase shift with respect to the fundamental| 7
| Power and energy mode: displays the active power, the reactive power, the apparent power, power factor, phase shift of power factor, etc| 11
| Trend mode: recording of the parameters selected in the Configuration menu.| 10
---|---|---
| Alarm mode: listing of recorded alarms exceeding the thresholds programmed in the configuration; recording of network blackouts with half- cycle resolution  (Vrms, Arms, Arms), determination of energy consumption overshoots,  monitoring of compliance with a power supply quality contract| 9
| Capture mode: monitoring the instantaneous change of power grid voltage current parameters, including the voltage current fluctuations, voltage current surge, sag and short supply interruption, temporary overvoltage, impact current, and current-voltage instantaneous distortion| 6

3.4.4. Other keys
The other keys have the following functions

Item Function Voi
Configuration key: device configuration and capture mode parameter

configuration, can
setting date and time, display, type of connection to the network, voltage ratio, current
sensor select, choice of thresholds to be detected, the definition of alarms to be detected,
choice of parameters to be detected| 5
| Snapshot mode: a snapshot of the current screen and retrieval of screens already stored| 12
| Help key: provides information about the functions and the symbols used for the current display mode| 13

3.5. Connectors
3.5.1. Measurement input connectors
Located on the top of the device, these connectors are distributed as followsUNI T UT285C Power Quality Analyzer -
Measurement

3.5.2. Charging interface and USB interface
Must be used with a special power adapter and USB cable

3.6. Power supply
3.6.1. Indication of battery level
The battery icon in the top right corner of the screen shows the battery level. The number of bars is proportional to the charge level.

Icon State of charge
Battery fully charged.
Low battery.
Mobile bars: battery charging.
The device is powered by mains and pre-charged.

When the battery level is too low, the following message is displayed:” Low battery, Instrument will soon turn OFF”.
If you do not reconnect the device to the mains, it is switched off one minute after this message appears.
3.6.2. Battery life
Battery life is 8 hours when the battery delivered with the device is fully charged.
3.6.3. Recharging the battery
The battery is recharged by the main power unit provided, and connected to the device by the jack (Figure 3-3).
Use only the main power unit provided with the instrument.
Charging a fully discharged battery takes about 5 hours. When the battery is recharged, the device continues to use mains power and does not discharge the battery.
3.6.4. The battery
The device is powered by a specific lithium battery (9.6V) having a nominal capacity of 4,500 mAh.
3.6.5. Mains operation
The battery is not essential when the unit is running on mains power. However, if mains power is cut off (there is no battery), during the recording process, for example, data may be lost.
3.7. The stand
A retractable stand (Figure 3-4) on the back of the instrument keeps the device at an angle of 60° from the horizontal

UNI T UT285C Power Quality Analyzer - Measurement1

3.8. Summary of functions
3.8.1. Measurement functions

  • The RMS values of AC voltages up to 1000 V between terminals.
  • The RMS values of AC currents up to 1000A (neutral included).
  • Sustaining voltages and currents (neutral included).
  • Minimum and maximum half-cycle RMS voltage and current.
  • Peak voltages and currents (neutral included).
  • Frequency of 50 Hz and 60 Hz networks.
  • Current and voltage peak factor (excluding neutral).
  • Calculation of the K factor (KF) (application to transformers when current harmonics are present).
  • Current and voltage distortion factor (DF) (excluding neutral).
  • Current and voltage total harmonic distortion (excluding neutral).
  • Active, reactive (capacitive and inductive), apparent power of each phase (excluding neutral).
  • Power factors (PF) and displacement power factors (PDF) (excluding neutral).
  • Short-term flicker (PST) (excluding neutral).
  • Active, reactive (capacitive and inductive), and apparent energy (excluding neutral).
  • Current and voltage harmonics (excluding neutral) up to order 50: harmonic ratio, RMS value, minimum and maximum, and sequence harmonics.
  • The apparent power of each harmonic up to order 50: harmonic ratio, RMS value, minimum and maximum.
  • The motor starting current and inrush currents

3.8.2. Main functions

  • Display of waveforms (voltages and currents).

  • Inrush Current function: displays parameters useful for the study of the starting of a motor.
    ★ Instantaneous current at the instant designated by the cursor.
    ★ Maximum instantaneous current (over the entire starting time).
    ★ RMS value of the half-cycle of the current on which the cursor is positioned.
    ★Maximum half-cycle RMS current (over the entire starting time).
    ★Time at which starting the motor commenced.

  • Screen captures (60 maximum).

  • Transients function. Detection and recording of transients (up to 150) between the user-defined start and stop dates and times. Recording of 4 complete cycles (one before the triggering event and three after).

  • Trend recording function (2GB memory with date-stamping and user-defined start and stop dates for recording, with a maximum of 100 recordings). Display, in bar chart or curve form, the means of many parameters vs. time, with or without minima and maxima.

  • Alarm function. List of recorded alarms (up to 12,800) exceeding thresholds defined in the configuration menu.
    User-defined alarm monitoring starts and stops times. Display the alarm trigger channel, minimum and maximum values after the trigger, duration

3.8.3. Configuration function

  •  Date and time settings.
  • Screen brightness and contrast settings.
  • Choice of curve colors.
  • Choice of reactive power and reactive energy calculation mode (with or without harmonics).
  • Choice of connection (single-phase, split-phase, 3- or 4-wire three-phase, 5-wire three-phase).
  • Choose current sensors and voltage ratio.
  • Trigger threshold values setting (voltage and current).
  • Monitoring parameters of trend diagram settings.
  • Choice of alarm monitoring parameters.
  • Erasure of data (total or partial).
  • Display software and hardware version numbers.
  • Choice of language (Chinese/English).

3.9. Abbreviations
Meanings of the symbols and abbreviations used

Symbol Designation Symbol Designation
AC and DC components. MAX Maximum true RMS.
AC component only. MIN Minimum true RMS.
DC component only. ms Millisecond (unit).
Φ Phase angle. PEAK Maximum (+) or minimum(-) voltage /current peak.
Inductive phase shift. PF Power factor.
Capacitive phase shift. PST Short-term flicker.
° Degree. RMS True RMS value (current or voltage).
-.+ Expert mode. T Time.
Sum of values. Tan Tangent.
L Phase (line). THE Total harmonic distortion.
% Percentage. Ucf phase-to-phase voltage crest factor.
A Ampere. Uh phase-to-phase voltage is harmonic.
Act Crest (peak) factor of current. Terms True RMS phase-to-

phase voltage.
Ah| Current harmonic.| USD| Total phase-to-phase voltage harmonic distortion.
---|---|---|---
Aid| K Factor (for transformers).| Uub| phase-to-phase voltage unbalance (34′).
Arms| True RMS current.| V| Phase-to-neutral voltage.
Add| Total harmonic distortion of current.| VA| Apparent power.
Aunt| Current unbalance (34′).| Vah| Apparent energy.
AVG| Mean value.| VAR| Reactive power.
CF| Peak factor (current or voltage).| with| Reactive energy.
DC| DC component (current or voltage).| If| Voltage crest (peak) factor.
PDF| Displacement power factor.| Vrms| True RMS phase-to-neutral voltage.
Hz| Frequency of network studied.| Ltd| Total harmonic distortion of phase-to-neutral voltage.
KF| See Akf.| Vung| Phase-to-neutral voltage unbalance (34′).
W| Active power.| Wh| Active energy.

USE

The device must be configured in accordance with §5 before any measurements are made.
The following precautions for use must be complied with:

  • Do not connect to any voltage exceeding 1,000 Vrms with respect to earth.
  • When connecting and disconnecting the battery, make sure that the measuring leads are disconnected and turned off.
Start-up

Press the key on the keypad to start the device.
After about 3 seconds, the Waveform screen is displayed.

UNI T UT285C Power Quality Analyzer - Measuremen2Figure 4-1: Waveform screen

The device is battery-powered only if the battery is adequately charged. If not, the alarm message “Low battery, the instrument will soon turn OFF” is displayed (see § 3.6). The device can be used with the mains power unit supplied with it connected to the jack; there is no need for the battery in this case.

Configuration

To configure the device, proceed as follows:
★ With the device on, press. The configuration screen appears.
★ Press or to select the parameter to be modified. Press to enter the selected sub-menu.

Figure 4-2: Configuration screen

Press or and or to browse and to confirm in the displayed sub-menu. See §5.3–§ 5.10 for details.
Note: The following points must be checked or adapted for each measurement:

Function See

Define the parameters of the calculation methods. (reactive power/ reactive energy).| §5.5
Select the type of connection (single-phase to three-phase, five-wire).| §5.6
Programming of the voltage ratios according to the type of current sensor connected.| §5.7
Transient triggering levels (transients mode).| §5.8
Values to be recorded (trend mode).| §5.9
Definition of alarm thresholds.| §5.10

Press to return to the Configuration screen.

Installation of leads

Connect the measuring leads to the device as follows:

  • Current measurement 4 current clamp corresponding connect to 4 channels current interfaces of L1/A, L2/B, L3/C, N/D. The current clamp muse has a corresponding connection to ensure the accuracy of measurement. Select the current clamp before measurement (see § 5.7).
  • Voltage measurement: The 5 voltage test wires according to the color corresponding connect to 5 voltage input interfaces of L1/A, L2/B, L3/C, E/GND, and N/D. Set the voltage ratio before measurement. (see § 5.7). The measuring leads must be connected to the circuit to be studied as shown by the following diagrams.

Single-phase network

Split-phase network

Figure 4-5: Split-phase connection

3- or 4-wire three-phase network

5-wire three-phase network

Connection procedure
★ Switch the instrument on.
★ Configure voltage ratio, select the current sensor, and the type of network concerned.
★ Connect the leads and current sensors to the unit.
★ Connect the earth and/or neutral lead to the network earth and/or neutral (when distributed) and connect the corresponding current sensor.
★ Connect the L1 phase lead to the network L1 phase and connect the corresponding current sensor.
★ If applicable, repeat the procedure for phases L2, and L3.
Note: complying with this procedure reduces connection errors to a minimum and avoids wasting time.

Waveform capture

Reminder: any screen can be saved (screen snapshot) by pressing the key (see § 12).
With the device powered up and connected to the network (voltage measurement leads and current sensor), press .

Display of the transients mode
See §6.2.

Display of the inrush current mode
See §6.3.

Display of harmonics

Reminder: any screen can be saved (screen snapshot) by pressing the key (see § 12).
With the device powered up and connected to the network (voltage measurement leads and current sensor), press .

Voltage harmonics display
See §7.2.

Current harmonics display
See §7.3.

Waveform measurements

Reminder: any screen can be saved (screen snapshot) by pressing the key (see § 12).
With the device powered up and connected to the network (voltage measurement leads and current sensor),
press .

Display of true RMS measurements
See §8.2.

Display of measurement of total harmonic distortion
See §8.3.

Display of PEAK factor measurements
See §8.4.

Display of Min and Max RMS, extreme values (voltage and current)
See §8.5.

Simultaneous display
See §8.6.

Display of vector diagram
See §8.7.

Alarm recording

Reminder: any screen can be saved (screen snapshot) by pressing the key (see § 12).
With the device powered up and connected to the network (voltage measurement leads and current sensors),
press .

Configuration of alarm mode
Configure the values to be monitored as described in §9.2.

Programming of an alarming campaign
See §9.3, configure start and shop time.

Auto stoppage
The alarm recording campaign is stopped automatically at the Stop date and time programmed by the operator.

Manual stoppage
See §9.3.3. Do not reach the preset stop date and time, the operator stop detection is active.

Viewing the alarm log
See §9.4.

Deleting the alarm log
See §9.5.

Trend recording

Reminder: any screen can be saved (screen snapshot) by pressing the key (see § 12).
With the device powered up and connected to the network (voltage measurement leads and current sensors), press .

Configuring a trend parameter
See § 10.3.

Programming a recording
See § 10.2.

Energy measurements

Reminder: any screen can be saved (screen snapshot) by pressing the key (see § 12).
With the device powered up and connected to the network (voltage measurement leads and current sensors), press .

Measurement of energies consumed
See §11.2.

Measurement of energies generated
See §11.6.

Transfer of data to the PC

The PC software can communicate with the device through a USB interface. Upload and store the measurements for future reference.
Note: The transfer does not delete the data, just copy it to the PC. When an alarming campaign is initiated or a search for transients, an inrush current capture, or a trend recording is pending or in progress, the PC cannot read the data.

Deleting data

Stored data may be deleted prior to a new test campaign, to free memory. See §5.11.

Turning off

Press the key to turn the device off.
When an alarming campaign is initiated or a search for transients, an inrush current capture, or a trend recording is pending or in progress, the device is not automatically switched off without confirmation.
The following message appears:

Are you sure want to turn OFF the instrument?
Recording in progress or in standby

Select Yes or No using the or key and press to validate.
★ If No is selected, the recording will continue.
★ If Yes is selected, the data recorded until that point are saved and the device is turned off.

Power supply

Recharging the battery
See §3.6.3.

Mains operation
See §3.6.5.

CONFIGURATION KEY

The key is used to configure the device. Before using the instrument, and thereafter as necessary, you must parameterize it. The stored configuration is retained when the instrument is switched off.

Available sub-menus

Select the sub-menu using the and keys and confirm by pressing . To return to the main screen, press

Figure 5-1: The sub-menu display screen

Name Sub-menu See
Date/Time Date and time settings. §5.3
Display Screen contrast and brightness settings. §5.4.1
Definition of voltage curve and current curve colors. §5.4.2

Calculation
method| Choice of reactive parameters (with or without harmonics).| §5.5
Connection| Choice of type of connection to the network (attention: some calculations depend upon the type of connection).| §5.6
Sensor and
ratios| Configuration of the ratios of the current sensors (0086 current clamps, 0406 current clamps, 068B current clamp, transformer).| §5.7.1
Configuration of voltage ratios.| §5.7.2
Transient
mode| Choice of current thresholds to be detected.| §5.8.1
Choice of voltage thresholds to be detected.| §5.8.2
Trend mode| Choice of parameters to be recorded for.| §5.9
Alarm Mode| Definition of alarms to be detected.| §5.10
Erase data| Choice of total or partial deletion of user data.| §5.11
About| Serial number, software, and hardware version numbers, and capacity of onboard memory card.| §5.12

Display language

To select the display language, press the yellow key under the corresponding icon on the screen (Figure 5-1). Select zh-CN as Chinese, and choose en as English. The yellow icon indicates the current user of the language.

Date/Time

This menu defines the system date and time. The display is as follows:

Figure 5-2: Date/Time menu

The Date/Time field is highlighted in yellow.

  • To change the date/time, press . The arrows show which value can be changed. To increment or decrement a value, press or.
    To select the value, press or . To confirm, press .

  • To modify the dating system, position the yellow cursor on the field using the or key. Press . The arrows show which value can be changed.
    Select DD/MM/YY or MM/DD/YY or YY/MM/DD, press or , then confirm by pressing .

To return to the Configuration main menu, press .

Display

Contrast/Brightness
This menu is used to define the contrast and brightness of the display unit. The display is as follows:

Figure 5-3: The Contrast/Brightness menu

The selected field is highlighted in yellow.

  • To modify the contrast, press or .
  • To move to the next field, press or .
  • To change the brightness, press or .

To return to the Configuration menu, press
.
Colors
The menu is used to define the colors of the voltage and current curves. The colors available are yellow, orange, red, pink, brown, green, and dark green, blue, sky blue, dark blue, light grey, and grey.

The display is as follows:

Figure 5-4: The Colours menu

The selected field is highlighted in yellow.

  • To select the color of the voltage and current curves, press or .
  • To move to the next field, press or .

To return to the Configuration menu, press

Calculation methods

determines whether or not harmonics are used in calculating the reactive parameters (powers and energies).

Figure 5-5: The Calculation methods menu

  • To select With harmonics or Without harmonics, press or
Connection

The menu is used to define how the device is connected, according to the type of network.

Figure 5-6: The Connection menu

Several electrical diagrams can be selected:

To configure the type of connection, proceed as follows:

  • Select Single-Phase, Two-Phase, 3- or 4-wire Three-Phase, or 5-wire Three-Phase by pressing or .
    To return to the Configuration menu, press
Sensors and ratios

Current sensors and ratios
The menu, invoked by the yellow key A icon, defines the current sensors and ratios. The device can select 3 current sensors, meanwhile, it can choose an optional current transformer, and set the turn ratio according to to need.

Figure 5-8: Current clamp and ratios screen in the Sensors and ratios menu

The possibilities are:

| 008B current clamp: 10mA~ 10A
---|---
| 040B current clamp: 0.10A~ 100A
| 068B current clamp: 1.0A~ 1000A
| 300F Flexible Coil Current Sensor (with Integrator) : 10A ~ 3000A

If using the optional current transformer, should be configured as follows:

  • Set transformer turns ratio: Into ratio setting, press .
    To select each field, use the or , To modify the turns ratio, use the or , (such as 2000/0001, device input 25mA, display 50.0A).

  • To validate, press .

Note: selecting optional transformer, device current port forbade input more than 500mA.

Voltage ratios
The menu, invoked by the V icon, defines the voltage ratios.

Figure 5-9: The Voltage Ratios screen in the Sensors and ratios menu

All the channels ratio can be set as the following:

  • (4V, 1/1) 4 channels with are 1:1 ratio.
  • (4V) 4 channels are the same ratio.
  • (3V+VN)L1\L2\L3 is the same ratio, N line independent setting ratio.
  • (V1+V2+V3+VN)4 channels independent setting ratio respectively.
    ★ To configure the ratios, press , then use the key and validate by pressing
    ★ To select the values, use the or key (highlighted in yellow).
    ★ To setting the ratio, press , The arrows appear.
    ★ To select the value, press or  . To increment or decrement a value, press or , then press to confirm.

To return to the Configuration main menu, press .

Transient mode

The mode is used to configure the voltage and current thresholds.

Current thresholds
The screen, displayed by pressing the A icon, is used to define the current thresholds.

Figure 5-10: The Current thresholds screen in the Transient Mode menu

★ The arrow indicates the channel of a cursor.
★ Use the or key to go from one channel to another, press appear , and start to change.
★ Press or select the change bit and threshold current unit(mA/A), To increment or decrement a value, press or
★ Press to confirm.

Voltage thresholds
The screen, displayed by pressing the V icon, is used to define the voltage thresholds.
All the voltage thresholds can be set as the following:

  • (4V)4 channels are the same threshold.
  • (3V+VN)L1\L2\L3 is the same threshold, N line independent setting threshold.
  • (V1+V2+V3+VN) 4 channels independent setting threshold respectively.

Figure 5-11: The Voltage thresholds screen in the Transient Mode menu

★ Press to enter ratio configure, and the arrows appear. Use or to select the above 3 different threshold combinations, then press to confirm.
★ To select the threshold, use the or key (highlighted in yellow).
★ To setting the threshold, press , The arrows appear and start to change.
★ Press or select the change bit and threshold unit(V/kV), To increment or decrement a value, press or . Then press to confirm.
To return to the Configuration main menu, press

Trend mode

The device has a recording function – key – (see § 10) for recording measured and calculated values (Urms, Vrms, Arms, etc.). Four independent configurations can be parameterized, depending on needs.
To select the desired configuration, press the yellow key corresponding to the icon. The active configuration is identified by the icon with a yellow background.
A configuration example is shown below:

Figure 5-12: In this example, only the Urms values are recorded in configuration 1

★ To define configuration 1, press the yellow key on the keypad corresponding to the icon. The icon appears on yellow ground.
★ To select the values, move the yellow cursor using the or and or .
★ Press to select/unselect, the red solid dot indicates is selected, the red hollow dot indicates is unselected.

The recordable values are:

Unit Designation.
Terms True RMS phase-to-phase voltage.
USD Harmonic distortion of the phase-to-phase voltage(2φ, 3φ).
Ucf Crest (peak) factor of phase-to-phase voltage(2φ, 3φ).
Uub Phase-to-phase voltage unbalance(2φ, 3φ).
Hz Network frequency.
Vrms True RMS phase-to-neutral voltage.
Ltd Total harmonic distortion of the phase-to-neutral voltage.
If Crest factor of phase-to-neutral voltage.
Vung Phase-to-neutral voltage unbalance(2φ, 3φ).
PST Short-term flicker.
Arms True RMS current.
Add Total harmonic distortion of the current.
Act Crest factor of current.
Aunt Current unbalance (2φ, 3φ).
KF K factor.
W Active power.
VAR Reactive power.
VA Apparent power.
PF Power factor.
PDF Displacement power factor.
Tan Tangent.
? See the comment below.

Features specific to the last two lines. These are recalled below:

Figure 5-13: These two lines involve harmonics

These two lines involve the recording of the harmonics of VAh, Ah, Vh, and Uh. You can select a range of orders of the harmonics to be recorded (between 0 and 50) for each of these quantities, and within this range, if desired, only odd harmonics. Proceed as follows:

  • To enter the value to be recorded: with the line highlighted in the yellow, press . The arrows appear. Select the value (VAh, Ah, Vh, and Uh) for which harmonics are to be recorded by pressing or “?” indicate is unselected. Confirm by pressing . The values field is highlighted in yellow.
    Press to go to the next field.

  • Select the starting harmonic order: with the field highlighted in yellow. Press , and the arrows appear. Press or to increment or decrement the harmonic order,  then validate by pressing. Press to go to the next field.

  • Select the last harmonic: (greater than or equal to the starting harmonic order) highlighted in yellow. Press , and The arrows appear. Press or to increment or decrement the harmonic order, then validate by pressing.
    Press to go to the next field.

  • Odd harmonics only: to select or deselect this function, press . The solid red dot identifies your selection:
    Selected, only odd harmonics between the two orders of harmonics specified in the previous points are recorded.
    Not selected, all harmonics (even and odd) between the two orders of harmonics specified in the previous points are recorded.

Figure 5-14: record-setting harmonic order

To return to the Configuration main menu, press
Proceed in the same way to define the other configurations.

Alarm mode

The screen defines the alarms used by the Alarm Mode function (see § 9). You can configure 40 different alarms.

Figure 5-15: The Alarm mode menu

  • Use the or  key to select a different setting alarm parameter group.
    To select the field, press . The arrows appear.

  • To select the values (Vah, Ah, Uh, etc., see table in § 5.9), press or  , then confirm with . The field is highlighted in yellow.

  • To navigate horizontally in the fields, use the or keys, then confirm by pressing . The arrows appear. Enter the values by pressing or  , then confirm by pressing
    . Do the same for all values to be entered in the fields.
    For each alarm to be defined, select:
    ★ The type of alarm (Vah, Ah, Uh, Vh, Tan, PF, PDF, VA, VAR, W, Athd, Utd, Vthd, KF, Hz, Aunb, Vunb, Vrms, Acf, Ucf, Vcf, PST, Arms, Arms, and Vrms – see the table of abbreviations in § 3.9).
    ★ The orders of harmonics (between 0 and 50, for Vah, Ah, Uh, and Vh).
    ★ The alarm filter (3L: 3 phases, L1, L2, L3 can be triggered individually; N: neutral can be triggered).
    ★ The direction of the alarm (> or < for Arms, Urms, Vrms, Hz only; otherwise only one direction is possible).
    ★ The triggering threshold of the alarm (the prefix of the unit of the alarm can be set in the following cases: W, VAR, VA, Arms, Arms, Vrms).
    ★ The minimum duration above or below the threshold required for alarm validation(can be set from 0 seconds to 99 minutes.
    ★ The hysteresis (The percentage increase or decrease from the corresponding alarm threshold, optional values are 1%, 2%, 5%, or 10%. If more than this percentage will stop the alarm – See § 17.2).

  • Press to select or cancel the alarm parameter set, the red solid dot indicate is selected, the red hollow dot indicates is unselected.

  • To display different alarm screen pages, press the yellow buttons corresponding to the icons.

  • To return to the Configuration menu, press .

Erase memory

The menu partially or totally deletes the data recorded in the device (trend recording, transients recording, inrush current, alarm, screen snapshots, device setting, and monitoring parameter setting).

Figure 5-16: Erase memory menu

  • For a partial deletion:
    ★ Select the parameters you want to delete by pressing the or key. The selected field is highlighted in yellow.
    ★ Press to select/unselect, the red solid dot indicates is selected, and the red hollow dot indicates is unselected.
    Note: If the Configuration is selected, the message “after the configuration is deleted, the device will be turned off” appears on the screen.
    ★ Select the submenu by pressing the yellow key corresponding to the icon. The icon displayed yellow indicates ready to delete, then press the yellow key corresponding to the icon to cancel the delete state.
    ★ In the state of ready to delete, press to confirm the deletion.

To return to the Configuration main menu, press .

  • To delete everything:
    ★ Select All parameters by pressing the yellow key on the keypad corresponding to the icon. The selection is identified by the red marks.
    Note: Since the Configuration is selected, the message “after the configuration is deleted, the device will be turned off” appears on the screen.
    ★ To uncheck all items selected, press the yellow key on the keypad corresponding to the icon, the red hollow dot indicates is unselected.

To return to the Configuration main menu, press .

About

The screen displays the serial number of the device, the firmware version, the DSP software version, the icon version, and the SD card capacity.

Figure 5-17: The About menu

To return to the Configuration menu, press

WAVEFORM CAPTURE KEY

Available sub-modes

The sub-modes are listed on the screen below and covered individually in the paragraphs that follow.

Figure 6-1: The screen when the Waveform Capture mode is entered

To enter the sub-modes, proceed as follows:
★ Select the mode by using the or key. The selected field is highlighted in yellow.
★ Confirm by pressing .

To return to the Waveform capture screen, press .

Transient mode

The model is used to record transients, view the list of recorded transients, and if necessary delete them. You can record up to 150 transients.

UNI T UT285C Power Quality Analyzer - FIG

Figure 6-2: The Detection schedule screen in the Transients mod

6.2.1. Programming and starting a search
Pressing the yellow key corresponding to the icon. The Detection schedule screen is displayedUNI T UT285C Power Quality Analyzer -
FIG1
6.2.1.1. Stage 1: configuration of parameter
★ Select the Start field using the or  key. The selected field is highlighted in yellow. Press to enter the values. The arrows▲▼ appear in the start date and time field of the programming of a campaign.
★ Press or to increment or decrement a value and or to go to the next item.
Note: The start date and time must be later than the current date and time.
★ Press **to validate the programmed Start date and time.
★ Select the
Stop field using the or key. The selected field is highlighted in yellow. Press to enter the values. The arrows▲▼ appear in the Stop date and time field of the programming of a campaign.
★ Press or to increment or decrement a value and or to go to the next item.
Note: The stop date and time must be later than the start date and time.
★ Press to validate the programming of the Stop date and time.
★ Instruments can store 150 sets of Transient records at the same time.
Proceed in the same way for the
Count. The count can contain up to 150 transient records.
Proceed in the same way for
Series name fields. The available alphanumeric characters are the uppercase letter from A to Z and the digits from 0 to 9. File name length up to eight characters.
★ To configure the voltage thresholds and current thresholds, press the yellow shortcut key to return to the Configuration menu.
To return to the Waveform capture screen, press .
6.2.1.2. Stage 2: starting the program
To begin monitoring the start and stop times you have defined, press the yellow key on the keypad corresponding to the
OK** icon.

  • The OK icon disappears and the icon appears instead.
  • The message Detection on standby is displayed until the start time is reached and the icon flashes in the screen’s top display bar.
  • When the start time is reached the message Detection in progress is displayed.
  • When the stop time is reached, the Detection schedule screen with the OK icon (bottom right-hand corner of the screen) is displayed again. It is then possible to program another search.
    Note: voltage and/or current transients are recorded according to the activation thresholds configured. If activation occurs on the current threshold, the current and voltage waveforms are recorded.
    To return to the Waveform capture screen, press .

6.2.1.3 . Intentional transients campaign stoppage

The search can be stopped deliberately before the stop date and time by pressing the yellow key on the keypad corresponding to the  icon (bottom right corner of the screen). The OK icon then reappears in the same place.
6.2.2. Display a transient
To display the recorded transients, proceed as follows

UNI T UT285C Power Quality Analyzer - FIG2 Figure 6-4: the Transient list screen

★ Select the line of the transient to be displayed using the or key. The selected field is bolded. Confirm by pressing . The screen displays the transients in the form of curves

★ Select the curve to be displayed using the or  key, and move the cursor using the or  , long press can move quickly.
To return to the Transient list screen, press .
6.2.3. Delete a transient
The icon is displayed only if a record has been made. To delete a transient, proceed as follows:

★ Select the transient to be deleted using the or key. The selected field is bolded.
★ Select the submenu by pressing the yellow key corresponding to the icon. The icon displayed yellow indicates ready to delete, then press the yellow key corresponding to the icon or cancel the delete state.
★ In the state of ready to delete, press to confirm the deletion.
6.3. Starting current mode
This mode is used to capture (record) inrush currents (voltage and current waveforms). In capture display mode, two sub-menus, RMS and PEAK, are available (see § 6.3.2).
The device keeps in memory only a single current inrush capture.
6.3.1. Programming the capture
To program the capture of an inrush current, select the submenu by pressing the yellow key of the keypad corresponding to the icon. The Capture schedule screen is displayed. UNI T UT285C Power Quality Analyzer
fig2

6.3.1.1. Stage 1: configuration of parameter
Proceed as follows:
★ Select the Start threshold field using the or or key. The selected field is highlighted in yellow. Press to enter the type of values. The arrows appear in the Start threshold field.
★ Press or to increment or decrement a value and press or to go to the next item.
★ Press to confirm Proceed in the same manner for the Triggering filter, Hysteresis, and Start time.
Note: for more information on hysteresis, refer to § 17.2.
6.3.1.2. Stage 2: starting the capture

To start the capture program at the start date and time you have defined press the yellow key on the keypad corresponding to the OK icon.

★ The OK icon disappears and the icon appears instead.
★ The message capture pending is displayed until the start time is reached and the icon flashes in the screen’s upper display bar.
★ When the start conditions are met and the start time is reached, the message Capture in progress is displayed and the memory occupation indicator appears at the top of the creek. (The black bar represents memory used; the white bar represents memory available.) The indicator is displayed only during the capture and disappears when the capture is completed.
★ If the capture is completed with a stop event (see conditions in § 17.5) or if the recording memory of the device is full, the capture stops automatically. Programming the capture mode and OK icon reappear.
Note: the device can keep in memory only a single inrush current capture. If you wish to make another capture, first, delete the previous one.
To return to the Waveform capture screen, press .
6.3.1.3. Intentional stoppage of capture
A capture can be stopped deliberately by pressing the yellow key on the keypad corresponding to the icon (bottom right corner of the screen). OK, the icon will appear in the same place.
6.3.2. Displaying the parameter of the capture
To display the characteristics of the capture, proceed as follows:

  • Select the submenu by pressing the yellow key corresponding to the icon. The Capture parameters screen is displayed.
No. Function See
-1 RMS mode  6.3.3
-2 PEAK mode 6.3.4
  •  Choose the type of display, RMS or PEAK, by pressing the yellow key corresponding to the icon. The device displays waveforms (current and voltage) on which you can move the time cursor and zoom in and out.
    ★ The instantaneous current and voltage at the time indicated by the cursor
    ★ The maximum instantaneous current (over the entire capture).
    ★ The RMS current in the half-cycle on which the cursor is positioned.
    ★ The maximum half-cycle RMS current (over the entire capture).
    ★ Maximum instantaneous value PEAK(over the entire starting time).
    ★ The starting time and the motor starting period.

Caution: The voltage must be present before the inrush current is proper for a stable and correct frequency lock.
6.3.3. True RMS current and voltage
The RMS mode displays the record of the trend of the true half-cycle RMS current and voltage and the frequency trend curve.
6.3.3.1. The 3A RMS display screen
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig4

6.3.3.2. The L1 RMS display screen

The following information is displayed:

UNI T UT285C Power Quality Analyzer fig5

Note: Filters L2 and L3 display the trend of the true half-cycle RMS current and voltage of phases 2 and 3. The screen is identical to the one displayed for filter L1.
6.3.4. Instantaneous inrush current
The PEAK mode is used to display the envelopes and waveforms of the inrush current capture.
6.3.4.1. The 4A PEAK display screen
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig6

6.3.4.2. The A1 PEAK display screen
UNI T UT285C Power Quality Analyzer fig7 Note: Filters A2 and A3 display the record of the current envelope of phases 2 and 3. The screen is identical to the one displayed for filter A1.

HARMONICS MODE

The key displays a representation of the harmonic ratios of the voltage, current, and apparent power, order by order. It can be used to determine the harmonic currents produced by nonlinear loads and analyze problems caused by harmonics according to their order (overheating of neutrals, conductors, motors, etc.).

7.1. Available sub-menus
The submenus are listed on the screen below and described individually in the paragraphs that follow.
The measurement type is selected using the yellow keys of the keypad below the screen. UNI T UT285C Power Quality Analyzer

7.2. Phase-to-neutral voltage
The sub-menu displays the harmonics of the phase-to-neutral voltage.
Note: The choice of curves to be displayed depends on the type of connection (see § 5.6):
★ Single-phase: no choice (L1).
★ Two-phase: 2L, L1, L2.
★Three-phase, 3-, 4-, or 5-wire: 3L, L1, L2, L3, -,+ ( expert mode).

The screen snapshots shown as examples were obtained with a three-phase connection. This observation also applies to the other sub-menus.
7.2.1. The 3L phase-to-neutral harmonics display screen
The following information is displayed:

UNI T UT285C Power Quality Analyzer fig

Display in expert mode (three-phase connection only – See 7.6) of the 3 phases (3×3L) or of L1, L2, or L3(*).
7.2.2. The L1 phase voltage harmonics display screen
The following information is displayed:

UNI T UT285C Power Quality Analyzer display screen

Note: Filters L2 and L3 display the harmonics of the phase-to-neutral voltage for phases 2 and 3, respectively. The screen is identical to the one displayed for filter L1.
7.3. Current
The sub-menu displays the harmonics of the current.
7.3.1. The 3L current harmonics display screen
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig1

7.3.2. The L1 current harmonics display screen
The following information is displayed:

UNI T UT285C Power Quality Analyzer fig2

Note: Filters L2 and L3 display the current harmonics of phases 2 and 3, respectively. The screen is identical to the one displayed for filter L1.
7.4. Apparent power
The sub-menu displays the harmonics of the apparent power.
7.4.1. The 3L apparent power harmonics display screen
The information is: UNI T UT285C Power Quality Analyzer
fig3

7.4.2. The L1 apparent power harmonics display screen
The information is:

UNI T UT285C Power Quality Analyzer fig4

Note: Filters L2 and L3 display the apparent power of the harmonics for phases 2 and 3, respectively. The screen is identical to the one displayed for filter L1.
7.5. Phase-to-phase voltage
The sub-menu is available only for three-phase connections when the voltage ratios of phases 1, 2, and 3 are equal. This sub-menu displays the harmonics of the phase-to-phase voltage.
7.5.1. The 3L phase-to-phase voltage harmonic display screen
The following information is displayed:

UNI T UT285C Power Quality Analyzer fig5

7.5.2. The L1 phase-to-phase voltage harmonics display screen
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig6

7.6. Expert mode
The model is available with a three-phase connection only when the ratios of the three phases are equal. It is used to display the influence of the harmonics on the heating of the neutral and rotating machines. To display expert mode press the or  keys of the keypad. The selection is highlighted in yellow and the screen simultaneously displays the expert mode.
From this screen, two sub-menus, and , are available (see next page).
7.6.1. The phase-to-phase voltage expert mode display screen
The sub-menu displays the influence of the harmonics of the phase-to-neutral voltage on the heating of the neutral and rotating machines.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig7

7.6.2. The current expert mode display screen
The sub-menu displays the influence of the harmonics of the current on the heating of the neutral and rotating machines.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig8

WAVEFORM KEY

The key is used to display the current and voltage curves, along with the values measured and those calculated from the voltages and currents (except for power, energy, and harmonics).
8.1. Available sub-menus
The sub-menus are listed on the screen below and described individually in the paragraphs that follow.
The type of measurement is selected using the yellow keys on the keypad below the screen.UNI T UT285C Power Quality Analyzer

8.2. Measurement of the true RMS value
The sub-menu displays the waveforms over one period of the signals measured and the true RMS voltage and current.
Note: The choice of curves to be displayed depends on the type of connection (see § 5.6):

  •  Single-phase: no choice (L1)
  •  Two-phase: 2V, 2A, L1, L2
  •  Three-phase, 3- or 4-wire: 3U, 3V, 3A, L1, L2, L3
  • Three-phase, 5-wire:

★ For : 3U, 3V, 3A, L1, L2, and L3
★ For : 3U, 4V, 4A, L1, L2, L3, and N

The screen snapshots shown as examples are those obtained with a three-phase 5-wire connection.

8.2.1. The 3U display screen
This screen displays the three phase-to-neutral voltages of a three-phase system.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig

8.2.2. The 4V RMS display screen
This screen displays the three phase-to-neutral voltages and the neutral-to- earth voltage of a three-phase system.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig1

8.2.3. The 4A RMS display screen
This screen displays the three-phase currents and the neutral current of a three-phase system.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig2

8.2.4 The RMS display screen for neutral
This screen displays the neutral voltage with respect to the earth and the neutral current.
The following information is displayed:

UNI T UT285C Power Quality Analyzer fig3

Note: L1, L2, and L3 display the current and voltage in phases 1, 2, and 3, respectively. The screen is identical to the one displayed for the neutral.
8.3. Measurement of total harmonics distortion
The sub-menu displays the waveforms of the signals measured over one full cycle and the total voltage and current harmonic distortion.

8.3.1. The 3U display screen
This screen displays the phase-to-phase voltage waveforms for one period and the total harmonic distortion values.
The following information is displayed:

UNI T UT285C Power Quality Analyzer fig4

8.3.2. The 3V display screen
This screen displays the phase-to-neutral voltage waveforms for one period and the total harmonic distortion values.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig5

8.3.3. The 3A display screen
This screen displays the phase current waveforms for one period and the total harmonic distortion values.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig6

Note: L1, L2, and L3 display the total current and voltage harmonic distortion for phases 1, 2, and 3, respectively.
8.4. Measurement of the PEAK factor
The sub-menu displays the waveforms of the signals measured over one period and the voltage and current peak factors.
8.4.1. The 3U CF display screen
This screen displays the phase-to-phase voltage waveforms of one period and the peak factors.
The following information is displayed: UNI T UT285C Power Quality Analyzer
fig7

8.4.2. The 3V display screen
This screen displays the phase-to-neutral voltage waveforms of one period and the peak factors.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig8

8.4.3. The 3A CF display screen
This screen displays the current waveforms of one period and the peak factors.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig9

Note: L1, L2, and L3 display the current and voltage peak factors for phases 1, 2, and 3, respectively.
8.5. Measurement of extreme and mean voltage and current
The sub-menu displays the maximum and minimum RMS voltage and current and the instantaneous positive and negative peak voltage and current.

8.5.1. The 3U Max.Min. -display screen
This screen displays the maximum and minimum RMS values and the instantaneous positive and negative phase-to-phase voltage peaks.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig10

Note: The MAX. and MIN. RMS measurements are calculated every half cycle (i.e. every 10 ms for a 50-Hz signal).
The measurements are refreshed every 300 ms.
8.5.2. The 4V Max.-Min. display screen
This screen displays the maximum and minimum RMS values and the instantaneous positive and negative peaks of the phase-to-neutral voltages and of the neutral.
The following information is displayed: UNI T UT285C Power Quality Analyzer
fig11

Note: The Max. and Min. RMS measurements are calculated every half cycle (i.e. every 10 ms for a signal at 50 Hz). The measurements are refreshed every 300 ms.

8.5.3. The 4A Max.-Min. display screen
This screen displays the maximum and minimum RMS values and the positive and negative instantaneous peak values of the phase and neutral currents.
The following information is displayed: UNI T UT285C Power Quality Analyzer
fig12

Note: The Max. and Min. RMS measurements are calculated every half cycle (i.e. every 10 ms for a signal at 50 Hz).
The measurements are refreshed every 300 ms.
8.5.4. The L1 Max.-Min. display screen
This screen displays the mean, maximum, and minimum RMS values and the instantaneous positive and negative peaks of the phase-to-neutral voltage and of the current of phase 1.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig13

Note: The Max. and Min. RMS measurements are calculated every half cycle (i.e. every 10 ms for a signal at 50 Hz).
The measurements are refreshed every 300 ms.
L2, L3, and N display the maximum and minimum RMS values and the instantaneous positive and negative peaks of the phase-to-neutral voltage and of the current for phases 2,  3, and of the neutral-to-earth. The screen is identical to the one displayed for the L1.
8.6. Simultaneous display
The sub-menu displays all of the voltage and current measurements (RMS, DC, THD, DF, CF, PST, and KF).
8.6.1. 3U simultaneous display screen
This screen displays the RMS, DC, THD, DF, and CF values of the phase-to-phase voltages.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig14

8.6.2. 4V simultaneous display screen
This screen displays the RMS, DC, THD, DF, CF, and PST values of the phase-to- neutral voltages and of the neutral.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig15

8.6.3. 4A simultaneous display screen
This screen displays the RMS, DC, THD, DF, CF, and KF values of the phase and neutral currents.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig16

8.6.4. L1 simultaneous display screen
This screen displays the RMS, DC, THD, DF, CF, and KF values of the phase and neutral currents.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig17

Note: L2 and L3 provide the simultaneous display of the current and voltage for phases 2 and 3, respectively.
8.6.5. Screen for simultaneous display of neutral
This screen displays the RMS voltage and current of the neutral, the DC component of the neutral voltage.

8.7. Display of phasor diagram
The sub-menu displays a vector representation of the fundamentals. It indicates their associated quantities: the modulus of the vectors, phases, and unbalances of the voltages and currents.
8.7.1. The 3V phasor diagram display screen
This screen displays a vector representation of the fundamentals. It indicates their associated quantities: the modulus of the vectors and unbalances of the phase-to-neutral voltages, the phase angle of phase-to-neutral voltage with respect to current.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig18

8.7.2. The 3U phasor diagram display screen
This screen displays a vector representation of the fundamentals. It indicates their associated quantities: the modulus of the vectors, phase angle, and unbalances of the phase-to-phase voltages.
The displayed information is identical to that described in § 8.7.1 but relative to the phase-to-phase voltages.
8.7.3. The 3A phasor diagram display screen
This screen displays a vector representation of the fundamentals. It indicates their associated quantities: the modulus of the vectors, phase angle, and unbalances of the currents.
The displayed information is identical to that described in § 8.7.1 but relative to the current.

8.7.4. The L1 phasor diagram display screen
This screen displays a vector representation of the fundamentals. It indicates their associated quantities: the modulus of the vectors of voltage and current of phase 1, phase angle of voltage with respect to the current of phase
1. The following information is displayed: UNI T UT285C Power Quality
Analyzer fig19

Note: L2 and L3 display a vector representation of the fundamentals. It indicates their associated quantities: the modulus of the vectors of voltage and current of phases 2 and  3, respectively, and the phase angle of voltage with respect to the current of phases 2 and 3, respectively.

ALARM MODE KEY

The mode detects overshoots of thresholds (Vrms, Arms, Arms, PST, Vcf, Ucf, Acf, Vunb, Aunb, Hz, KF, Vth, And, Add, |W|, |VAR|, VA, |cos Φ|, |PF|, |tan Φ| Vh, Uh,  Ah, and |VAh|) programmed in the configuration mode.
The user should program an alarm threshold (hysteresis) first and then start the alarm campaign. The values to be monitored:
★were defined by the Configuration / Alarm mode screen (see § 5.10).
★select the setting parameters (the red solid dot indicates selected, and the red hollow dot indicates not selected).
You can capture over 12,800 alarms. Stored alarms can subsequently be transferred to a PC to save (see the corresponding manual).

9.1. Available submenus
The submenus are listed on the screen below and described individually in the paragraphs that follow.
The sub-menus are selected using the yellow keys on the keypad below the screen.

UNI T UT285C Power Quality Analyzer

The OK and icons have the following functions:
★OK: Validating the programming of a campaign and starting the alarm campaign (see § 9.3.2).
★ : Voluntary stoppage of alarm campaign (see § 9.3.3).
9.2. Alarm mode configuration
The  submenu displays the list of alarms configured (see § 5.10). This shortcut key lets you define or change alarm configurations.

The following information is displayed:UNI T UT285C Power Quality Analyzer
Alarm mode

Reminder: Use the or keys to browse vertically in the fields. Use the or keys to browse horizontally in the fields.
Proceed as follows to configure an alarm:
★ Select the field by pressing . The arrows appear.
★ Enter values by pressing or, then validate via. The field is highlighted in yellow.
Do the same for all values to be entered in the fields.
★ Activate the configured alarm by placing the yellow cursor on the browsing column and pressing . The red solid dot indicates selected. When the condition is met the alarm can be triggered, generating the alarm log.
Note: To deactivate the alarm, repeat the last step.
★Press to return to the Programming a campaign screen.
9.3. Programming an alarming campaign
The submenu is used to specify the start and stop times for an alarming campaign.

UNI T UT285C Power Quality Analyzer alarm campaign

9.3.1. Stage 1: programming the start/stop times
Proceed as follows:
★ Select the Start field using the or key. The selected field is highlighted in yellow. Press  to enter the values. The arrows appear in the start date and time campaign programming field.
Press or  to increment or decrement a value and or  to move to the next item.
Note: The start date and time must be after the current date and time.
★ Press to validate the programming of the Start date and time.
★ Select the Stop field using the or key. The selected field is highlighted in yellow. Press to enters the values. The arrows appear in the Stop date and time campaign programming field. Press or to increment or decrement a value and or to move to the next item.
Note: The Stop date and time must be after the start date and time.
★Press to validate the programming of the Stop date and time.
9.3.2. Stage 2: Starting the alarm campaign
Press the yellow key corresponding to the OK icon to start the alarm campaign between the start and stop times you specified.

  • The OK icon disappears and the icon appears in its place.
  • The Campaign on standby message is displayed while awaiting the start time and the icon blinks in the screen’s top display bar.
  • The Campaign running message is displayed when the Start time is reached.
  • The Campaign schedule screen and OK icon are displayed when the Stop time is reached. You can then program another campaign.

9.3.3. Voluntary stoppage of alarm campaign
The alarm campaign can be voluntarily stopped before the Stop date and time by pressing the yellow key corresponding to the icon (bottom right-hand corner of the screen). The OK icon then reappears in its place.

9.4. Viewing the alarm log
The submenu displays the alarm log. The log can contain up to 12,800 alarms. Press the yellow key corresponding to the icon to view this alarm log.
Note: the type of connection selected in the mode does not affect which alarm filters can be chosen and which parameters are monitored. Users are responsible for these choices.
The following information is displayed:UNI T UT285C Power Quality Analyzer
Alarm list screen

Reminder: At the alarm log, the default units of monitored parameters corresponding to the trigger threshold and trigger amplitude are as follows:
Table 9-1

Monitored parameters| Default
units| Units with the suffix| Example
---|---|---|---
Arms| A| m: express mA
k: express kA| 2.5: express 2.5A
423m: express 423mA
Vrms/Urms| V| k: express kV| 326: express 326V
1.2k: express 1.2kV
W/VAR/VA| W/Var/VA| K: express kW/kVar/kVA
M: express MW/MVar/MVA| W parameter: 315 express 315W
W parameter: 5.8k express 5.8kW
Hz| Hz| | 50.00: express 50.00Hz

9.5. Deleting the alarm log
The submenu is used to delete the whole log. To do this, proceed as follows:
Select the submenu by pressing the yellow key corresponding to the icon. The icon displayed yellow indicates ready to delete, then press the yellow key corresponding to the icon to cancel the delete state. The icon displayed in gray indicates don’t delete.
In the state of ready to delete, press to delete the whole alarm log. The log is empty.

TREND MODE KEY

The mode records changes to parameters previously specified in the Configuration/Trend mode screen (see § 5.9).
10.1. Available sub-menus
The sub-menus are listed on the screen below and described individually in the paragraphs that follow.
The sub-menus are selected using the yellow keys on the keypad below the screen.

UNI T UT285C Power Quality Analyzer Trend mode screen

The OK icon confirms the programming of a recording (see § 10.2).

10.2. Programming and start recording
The submenu specifies the parameters of a new recording campaign. UNI T
UT285C Power Quality Analyzer recording screen

10.2.1. Stage 1: programming of parameters
Proceed as follows:
★ Select the Configuration field using the or  keys. The selected field is highlighted in yellow. Press to enters the type of configuration. The arrows appear.
★ Select the configuration to be used by browsing using the or keys. Press to validate.
Reminder: Configurations to were defined in the Configuration / Trend mode screen (see § 5.9). The configuration procedure is also described in § 10.3.
★ Select the Start field using the or keys. The selected field is highlighted in yellow. Press to enter the values. The arrows appear in the recording start date and time programming field. Press or increment or decrement a value and or switch year, month, day, hour, or minute.
Note: The start date and time must be later than the current date and time.

★ Press to validate the programming of the Start date and time.
★ Select the Stop field using the or keys. The selected field is highlighted in yellow. Press to enter the values. The arrows appear in the recording stop date and time programming field. Press or increment or decrement a value and or  to switch year, month, day, hour, or minute.
Note: The stop date and time must be later than the start date and time. The longest recording time can be programmed see § 10.6.4.
★Press to validate the programming of the Stop date and time.
★Select the Period field using the or keys and press to enter the value. The arrows appear.
★Press or to increment or decrement the possible values (1 s, 5 s, 20 s, 1 min, 2 min, 5 min, 10 min, or 15 min).
★Press to validate.
Note: The recording interval period is the time over which the measurements of each recorded value are averaged (arithmetic mean). That is how often a data record is.
★ Press or  to highlight the Name box in yellow and press to enter edit mode. Enter the name of the recording (not more than 8 characters, records shall use a  different name, file name intermediate cannot appear spaces).
The available alphanumeric characters are the uppercase letters from A to Z and the digits from 0 to 9. Use the or  keys to display a character and or to move to the adjacent character.
★Press to validate the name.
10.2.2. Stage 2: starting a programmed recording

  • Press the yellow key corresponding to the OK icon (bottom right-hand corner of the screen) to begin recording between your specified start and stop times.
    The OK icon disappears and the icon appears in its place.

  • The Recording on standby message is displayed while awaiting the start time and the icon blinks in the screen’s top display bar.

  • The Recording running message is displayed when the start time is reached.

UNI T UT285C Power Quality Analyzer while recording

  • The Recording schedule screen and OK icon (bottom right-hand corner of the screen) reappear when the stop
    time is reached. The OK icon then reappears in its place.

10.2.3. Voluntary stoppage of recording in progress
Recording can be voluntarily stopped before the stop date and time by pressing the yellow key corresponding to the icon (bottom right-hand corner of the screen). The  OK icon then reappears in its place.

10.3. Trend mode configuration
The submenu displays the list of trend recording configurations (see § 5.9). This shortcut key lets you specify or modify the trend recording configurations.
The following information is displayed:

UNI T UT285C Power Quality Analyzer configuration
screenProceed as follows to configure a recording:
Example for configuration 1:
★ Press the yellow key corresponding to the icon. It is displayed on a yellow ground.
★ Select values by moving the yellow cursor using the or  and or keys, then press to validate. The red solid dot indicates validation.
Reminder: You can record the following values:

Unit Designation
Terms RMS phase-to-phase voltage(2φ, 3φ).
Utd Total harmonic distortion of the phase-to-phase voltage(2φ, 3φ).
Ucf Crest (peak) factor of phase-to-phase voltage(2φ, 3φ).
Uub Phase-to-Phase voltage unbalance(2φ, 3φ).
Hz Network frequency.
Vrms RMS phase-to-neutral voltage.
Ltd Total harmonic distortion of the phase-to-neutral voltage.
If Crest factor of phase-to-neutral voltage.
Vung Phase-to-neutral voltage unbalance(2φ, 3φ).
PST Short-term flicker.
Arms RMS current.
Add Total harmonic distortion of the current.
Act Crest factor of current.
Aunt Current unbalance(2φ, 3φ).
KF K factor.
W Active power.
VAR Reactive power.
VA Apparent power.
PF Power factor.
Cosφ The phase shift of power factor.
Tanφ Tangent.
? See the comment below.

Features specific to the last two lines.
These are recalled below:

UNI T UT285C Power Quality Analyzer fig

These two lines involve the recording of Vah, Ah, Vh, and Uh variable harmonics. You can select the ranks of harmonics to be recorded (between 0 and 50) for each of these harmonics and odd-only harmonics within this range. Proceed as follows:

  • To enter the value to be recorded: with line o? highlighted in yellow, press . The arrows appear. Select the value (Vah, Ah, Vh, and Uh) for which harmonics are to be recorded by pressing or    . The red solid dot identifies your selection.
    Confirm by pressing . The values field is highlighted in yellow.

  • To select the starting harmonic order: with the field highlighted in yellow, press . The arrows  appear.

Select the order in which the harmonics are to be recorded by pressing or  , then validate by pressing . Press or go to the next field.

  • To select the last harmonic: with the second field (greater than or equal to the starting harmonic order) highlighted in yellow, press . Select the highest harmonic order to be recorded by pressing or , then validate by pressing . Press or go to the next field.

 For the odd harmonics only:
To select or deselect this function, press . The red solid dot identifies your selection:
★ selected, only odd harmonics between the two orders of harmonics specified in the previous points are recorded.
★ not selected, all harmonics (even and odd) between the two orders of harmonics specified in the previous points are recorded.

10.4. Viewing the recording list
The submenu displays recordings already made. Press the yellow key corresponding to the icon to see the list.
The following data is displayed:UNI T UT285C Power Quality Analyzer
fig1

10.5. Deleting recordings
The submenu is used to delete recordings. Proceed as follows:
★Select the recording to be deleted using the or keys. The selected field is bolded.
★Select the submenu by pressing the yellow key corresponding to the icon. The icon displayed yellow indicates ready to delete, then press the yellow key corresponding to the icon to cancel the delete state.
The icon displayed in gray indicate doesn’t delete.
★In the state of ready to delete, press to validate the deletion.

UNI T UT285C Power Quality Analyzer fig2

10.6. Viewing the records
10.6.1. Characteristics of the record

UNI T UT285C Power Quality Analyzer fig3

10.6.2. Trend curvesUNI T UT285C Power Quality Analyzer
fig4

Remark: Values of the cursor are dashes “—-” indicate errors or missing values in the record.
The display period of this curve is 20 seconds. Since the period of the record is one second, each point of this curve corresponds to a value recorded in a one-second window once 20 seconds. There is therefore a substantial loss of information (19 values out of 20), but the display is rapid.
With the increase in the display period, the loss values will be more. In this case, the user can select to activate the    MIN-AVG-MAX mode. After the MIN- AVG-MAX mode is activated, each point of the curve represents the mean of the total sampling points every period(such as the display period is 20 seconds, the sampling period is 1 second, each
display point of the curve represents the mean of 20 values recorded every second.).

UNI T UT285C Power Quality Analyzer fig5

Figure 10-11: Vrms with MIN-AVG-MAX

With the MIN-AVG-MAX mode activated, each point of this curve represents the arithmetic mean of 60 values recorded. This display is therefore more precise because there is no loss of information, but it is slower(display time

UNI T UT285C Power Quality Analyzer fig6

With the MIN-AVG-MAX mode not activated, display the curve of 60 values recorded by the cursor, the display is rapid.

UNI T UT285C Power Quality Analyzer fig7

UNI T UT285C Power Quality Analyzer fig8

This curve differs slightly from the previous one because, with the MIN-AVG- MAX mode, there is no loss of information. UNI T UT285C Power Quality
Analyzer fig9

Energy calculation steps:
★ Press the yellow key corresponding to the icon to activate the energy summation mode. The current cursor time is the starting time of the energy calculation.
★ Press the or  to move the cursor. The stopping time of the energy calculation points to the cursor time, the device calculates the energy between the start time and stop time automatically.
Note: the cursor moves left and cannot exceed the location of the starting time.

10.6.3. The needing time for display the curve in the different scales.
The following table indicates the time needed to display the curve on the screen as a function of the width of the display window for a recording period of one second:

width of the display window 60 points or increments)| Grid increment| Typical waiting time
---|---|---
5 days| 2 hours| 30 seconds
2.5 days| 1 hour| 15 seconds
15 hours| 15 minutes| 4 seconds
10 hours| 10 minutes| 2 seconds
5 hours| 5 minutes| 1 second
1 hour| 1 minute| 1 second
20 minutes| 10 seconds| 1 second
5 minutes| 5 seconds| 1 second
1 minute| 1 second| 1 second

★ to press the or key to change the scale of the display
★ press the or key to move the cursor
★ press the or key to change the display phase curve.
But note that this may restart the loading/calculation of the values from the beginning.
10.6.4. The longest recording time can be programmed
The longest time is based on the number of recording parameters selected and the sampling period, the typical condition is as follows:

parameter of selected| sampling period| The typical longest time can be programmed
---|---|---
All parameters (total 123)| 1 second| 10 days
1~20 parameters| 1 second| 62 days
All parameters (total 123)| 5 seconds| 50 days
1~20 parameters| 5 seconds| 300 days
All parameters (total 123)| 1 minute| 600 days
1~20 parameters| 1 minute| 3600 days

The above table indicates that the selected parameters are fewer, the sampling period is greater, and the longest recording time is longer.

POWER AND ENERGY KEY

The key displays power- and energy-related measurements.
11.1. Available sub-menus
The sub-menus are listed on the screen below and described individually in the paragraphs that follow.
The sub-menus are selected using the yellow keys on the keypad below the screen.

UNI T UT285C Power Quality Analyzer fig10

11.2. Energy consumed
The sub-menu displays the active power, the reactive powers (capacitive and inductive), and the apparent we r.
11.2.1. The energies consumed screen for the 3 phases (3L)
This screen displays the following information:

UNI T UT285C Power Quality Analyzer fig11

Unit Designation
W Active power.
Wh Active energy consumed.
VAR Reactive power (inductive or capacitive ).
with Reactive energies consumed (inductive or capacitive ).
VA Apparent power.
--- ---
VA Apparent energy consumed.

11.2.2. The energies consumed screen for phase L1
This screen displays the following information: UNI T UT285C Power Quality
Analyzer fig12

Unit Designation
W Active power.
Wh Active energy consumed.
VAR Reactive power (inductive or capacitive ).
with Reactive energies consumed (inductive or capacitive ).
VA Apparent power. (∑: sum of 3 phases)
VA Apparent energy consumed.
PF Power factor.
Cosφ The phase shift of the power factor
Tanφ Tangent factor
φVA The phase shift of phase-to-neutral voltage with respect to current.

Note: Filters L2 and L3 display the same information for phases 2 and 3. screen displays total power and energy consumed values for the 3 phases.
11.3. Power factor display screen
This screen page is available only with the 3L filter. To display the information, press the yellow key on the keypad corresponding to the icon.
The following data is displayed:

UNI T UT285C Power Quality Analyzer fig13

11.4. The sum of energies consumed display screen
To display the information, select the icon of the right-hand filter. This screen displays the following information: UNI T UT285C Power Quality
Analyzer fig14

Unit Designation
D Total active power.
W Total active energy consumed.
T Total reactive power, inductive or capacitive .
Wh Total reactive energies consumed, inductive or capacitive .
T Total apparent power.
VAR Total apparent energy consumed.

11.5. The arithmetic mean values of the power factor display screen
To display the arithmetic mean values for the 3 phases (for power factor, the phase shift of power factor, and tangent), select the icon of the right-hand button.
This screen displays the following information:

UNI T UT285C Power Quality Analyzer fig15

11.6. Energies generated
The sub-menu displays the active power, the reactive powers (capacitive and inductive), the apparent power, and all associated energies generated.
11.6.1. The energies generated screen for the 3 phases (3L)
This screen displays the following information: UNI T UT285C Power Quality
Analyzer fig16

Unit Designation
W Active power.
Wh Active energies are generated.
VAR Total reactive power, inductive or capacitive
with Total reactive energies generated, inductive   or capacitive
VA Total apparent power.
V Total apparent energy generated.
PF Power factor.
Cosφ The phase shift of power factor.
Tanφ Tangent factor.
φVA The phase angle between voltage and current.

11.6.2. The energies generated display for phase L1
This screen displays the following information:UNI T UT285C Power Quality
Analyzer fig17

Unit Designation
W Active power.
Wh Active energies are generated.
VAR Total reactive power, inductive or capacitive .
with Total reactive energies generated, inductive or capacitive
VA Total apparent power.
VA Total apparent energy generated.
PF Power factor.
Cosφ The phase shift of power factor.
Tanφ Tangent factor.
φVA The phase angle between voltage and current.

Note: Filters L2 and L3 display the same information for phases 2 & 3. ∑ screen displays total power and energy generated values for the 3 phases.
11.6.3. The sums of energies generated display screen
To display the information, select the ∑ icon.
This page displays:
★The total active power,
★The total active energy generated,
★The total reactive power, inductive   or capacitive ,
★The total reactive energies generated (inductive and capacitive ),
★The total apparent power,
★The total apparent energy generated.
11.7. Starting energy metering
To start metering, press the yellow key on the keypad corresponding to the icon:

UNI T UT285C Power Quality Analyzer fig18

11.8. Stopping energy metering
To stop energy metering, press the yellow key on the keypad corresponding to the icon. UNI T UT285C Power Quality Analyzer fig19

11.9. Reset of energy metering
To reset metering, press the yellow key on the keypad corresponding to the icon, The icon displayed yellow indicates ready to delete, then press the yellow key corresponding to the icon to cancel the delete state.
In the state of ready to delete, press the key to confirm. All energy values (consumed and generated) are reset.
Note: refer to the 4-quadrant power diagram in § 17.3.

SCREEN SNAPSHOT KEY

The key can be used to:
★Capture a maximum of 60 screens for future reference (see § 12.1).
★display previously saved screen snapshots (see § 12.2).
Saved screens may then be transferred to a PC using the USB.
12.1. Screen snapshots
Press for approx. 3 seconds to shoot any screen (including the , , , , , and mode screens).

During the capture, the icon appears in the top left corner of the screen instead of the icon for the active mode ( , , , , , , ,). The active mode icon reappears when you release the key: the device has saved the image.
Reminder: the device can save a maximum of 60 screen snapshots. If the user attempts to take the 61st screen snapshot, first, upload the pictures you need to the computer through USB, then delete the device’s snapshots before capturing new pictures.

12.2. Handling of screen snapshots
This handling concerns stored screen snapshots, i.e.:
★Display the list of screen snapshots (see § 12.2.2).
★Viewing of one of the screen snapshots (see § 12.2.3).
★Deletion of one or more of the screen snapshots (see § 12.2.4).
12.2.1. Available functions
To enter screen snapshot mode, briefly press the key.
Reminder: holding the key down for approximately 3 seconds triggers the screen snapshot function (See § 12.1).

UNI T UT285C Power Quality Analyzer fig21

12.2.2. Viewing the list of snapshots
Press briefly to display this list. The screen presents the list of snapshots (see figure 12-2).
12.2.3. Viewing a snapshot from the list
To view a snapshot, proceed as follows:

★ Press . The icon is active and the snapshot list screen is displayed (see figure 12-2).
★ Select the snapshot to be viewed using the or and or keys. The date and time of the selected snapshot are bolded.
★ Press to display the selected snapshot. The top left corner of the screen displays the icon, alternating with the icon corresponding to the active mode (such as harmonic mode).
★ Press to return to the list of screen snapshots.
12.2.4. Deleting a snapshot from the list

To delete a snapshot, proceed as follows:
From the list of snapshots (see Figure 12-2 for example).
★ Select the snapshot to be deleted using the or and or keys. The date and time of the selected snapshot are bolded.
★ Press the yellow key on the keypad corresponding to the icon, The icon displayed yellow indicates ready to delete, then press the yellow key corresponding to  the icon to cancel the delete state.
★ In the state of ready to delete, press the key to confirm.
Press to delete the selected snapshot. The snapshot is deleted from the list.

HELP KEY

The key provides information about the functions and symbols used in the current display mode.
The following information is displayed:UNI T UT285C Power Quality Analyzer
fig

DATA UPLOADED TO THE COMPUTER

To install a program, use the CD, then follow the on-screen instructions. Then connect the device to the PC using the USB cord supplied with the device, start the device, then open the data software to click on the computer’s Power Quality Analyzer.exe. Wait for the software to automatically search and connect the device. For directions for using the data export software, refer to its user manual.
Note: Note: The transfer does not delete the data, just copy it to the PC. At alarm/trend chart record/transient capture mode  (pending or ongoing), the PC cannot read the data.

GENERAL SPECIFICATIONS

15.1. Housing

Housing Rigid shell over-molded with a red thermo-adhesive elastomer.
Connectors 5 voltage measurement sockets.

4 special current connectors.
One connector for the specific mains power unit.
One connector for the USB link.
One connector for the SD memory card. This connector is located in the battery compartment on the back of the device.
Keys| Function, navigation, and mode. Can be used with gloves on.
Hand strap| Located on the side of the device, use to operate more conveniently.
Stand| To hold the device in an inclined position.
Battery cover| To access the battery, on the back of the instrument.
dimensions| Overall: 240×170×68mm
Screen: 640×480 pixels
W×H: 118mm×90mm;
Diagonal: 148mm
Weight| Host: 1600 g (with battery).

15.2. Power supply
15.2.1. External mains power supply

Range for use| Input AC100V-240V, 50Hz/60Hz, Output DC12V, Maximum output current 3A.
---|---
Maximum input power| 36VA

15.2.2. Battery supply
The device can be used without a connection to mains power. The battery also makes it possible to use the device during power outages.

Battery Rechargeable lithium-ion battery pack 9.6V
Capacity 4500 mAh
Life at least 500 charge-discharge cycles.
Charging current approx. 0.6A
Charging time approx. 8 hours
Service T° [0 °C ; 50 °C].
Charging T° [10 °C ; 35 °C].
Storage T° Storage ≤30 days:[-20 °C; 50 °C]

storage for 30 to 90 days:[-20 °C ; 40 °C].
storage for 90 days to 1 year: [-20 °C ; 30 °C].

15.2.3. Consumption

At 10% luminosity 410 mA
At 50% luminosity 490 mA
At 100% luminosity 590 mA

15.3. Range for use
15.3.1. Environmental conditions
15.3.1.1. Climatic conditions
The following chart shows conditions relating to ambient temperature and humidityUNI T UT285C Power Quality Analyzer

Caution: at temperatures above 40°C, the device must be powered by the battery alone OR by the mains power unit alone; use of the device with both the battery AND the mains power unit is prohibited.
15.3.1.2. Altitude
Use: [0 m; 2 000 m] Storage: [0 m; 10 000 m] 15.3.2. Mechanical conditions
Under IEC 61010-1, the device is regarded as a PORTABLE DEVICE (HAND- CARRIED ).

  • Operating position: any position.
  • Reference position in operation: on a horizontal plane, resting on its stand or lying flat.
  • Rigidity (IEC 61010-1): the force of 30 N applied to any part of the housing, the device is supported (at 40°C).
  • Fall (IEC 61010-1): 1 m in presumed worst-case position; the requirement is no permanent mechanical damage and functional degradation.
  • Tightness: IP 50 as per NF EN 60529 A1 (IP2X electrical protection for the terminals).

15.3.3. EMC electromagnetic compatibility
15.3.3.1. Immunity as per IEC 61326:1-2006

  • Immunity to electrostatic discharges (as per IEC 61000-4-2)

1st
level:| Severity:| 4 kV in contact
---|---|---
Requirements:| CRITERION A
2nd
level:| Severity:| 8 kV in air
Requirements:| CRITERION A

 Immunity to radiated fields (as per IEC 61000-4-3 and IEC 61000-4-8)

Severity:     10V.m
Requirements  CRITERION B

 Immunity to rapid transients (IEC 61000-4-4)

Severity:  2 kV on voltage inputs and power supply

   1 kV on current input
Requirements:|  CRITERION A

 Immunity to electric shocks (as per IEC 61000-4-5)

Severity  2 kV on voltage inputs in differential mode

   1 kV on voltage inputs in common mode
Requirements:| CRITERION A

 Conducted RF interference (as per IEC 61000-4-6)

Severity: 3 V on voltage inputs and power supply
Requirements: CRITERION A

 Voltage interruption (as per IEC 61000-4-11)

   Severity:  100% loss over one period of the power supply
   Requirements:    CRITERION A

15.3.3.2. Emissions as per IEC 61326:1-2006
Class A equipment.
15.4. User safety

  • Application of safety rules as per IEC standard 61010-1 (protective impedances on voltage inputs).
  •  Pollution type 2.
  • Double insulation on ****/O with respect to earth ( symbol).
  • Double insulation between the voltage inputs and power supply and the other ****/O ( symbol).

FUNCTIONAL CHARACTERISTICS

16.1. Reference conditions
This table indicates the reference conditions of the quantities to be used by default in the characteristics.

Ambient temperature (23±2)°C
Humidity (relative humidity 40%~ 60%
Atmospheric pressure [860hPa~ 1060hPa]
Phase-to-neutral voltage [(50±1%) Vrms; (500±1%) Vrms] without DC (< 0.5 %)
Frequency of electrical network 50Hz±0.1Hz, 60Hz±0.1Hz
Phase shift 0° (active power ), 90° (reactive power)
Harmonics <0.1%
Voltage unbalance <10%
Voltage ratio 1
Current ratio 1
Power supply Battery only
Electric field <1V/m
Magnetic field <40A/m

16.2. Electrical characteristics
16.2.1. Voltage input characteristics
0 Vrms to 1000 Vrms AC+DC phase-to-neutral and neutral-to-earth.
0 Vrms to 2000 Vrms AC+DC phase-to-phase. (on condition of compliance with 1000 Vrms with respect to earth in CAT III).

16.2.2. Current input range
008B current clamp: 10mA~ 10A.
040B current clamp: 0.10A~ 100A.
068B current clamp: 1.0A~ 1000A.
Optional current transformer: device input current 1mA~ 500mA.
16.2.3. Characteristics of the device alone (excluding the current sensor)
Respectively introduce the following data (on the basis of base conditions and the ideal current sensors, perfectly linear, no phase shift).

Measurement| Range| Display resolution| The maximum error in the range of the reference
---|---|---|---
Frequency| 40Hz~ 70Hz| 0.01Hz| ±(0.03)Hz
True RMS phase-to-neutral voltage| 1.0V~ 1000V| Min resolution 0.1V| ±(0.5%+5dgt)
---|---|---|---
True RMS phase-to-phase voltage| 1.0V~ 2000V| Min resolution 0.1V| ±(0.5%+5dgt)
DC voltage| 1.0V~ 1000V| Min resolution 0.1V| ±(1.0%+5dgt)
True RMS current| 10mA~ 1000A| Min resolution 1mA| ±(0.5%+5dgt)
The peak of phase-to-neutral voltage| 1.0V~ 1414V| Min resolution 0.1V| ±(1.0%+5dgt)
The peak of phase-to-phase voltage| 1.0V~ 2828V| Min resolution 0.1V| ±(1.0%+5dgt)
Current peak| 10mA~ 1414A| Min resolution 1mA| ±(1.0%+5dgt)

Peak factor

| 1.00~ 3.99| 0.01| ±(1%+2dgt)
4.00~ 9.99| 0.01| ±(5%+2dgt)
Active power| 0.000W~ 9999.9kW| Min resolution 0.001W| ±(1%+3dgt) Cosφ≥0.8
±(1.5%+10dgt) 0.2≤Cosφ<0.8
Reactive power, inductive or capacitive| 0.000VAR~9999.9kVAR| Min resolution 0.001VAR| ±(1%+3dgt) Sinφ≥0.5
±(1.5%+10dgt) .2≤Sinφ<0.5
Apparent power| 0.000VA~9999.9kVA| Min resolution 0.001VA| ±(1%+3dgt)
Power factor| -1.000~ 1.000| 0.001| ±(1.5%+3dgt)Cosφ≥0.5
±(1.5%+10dgt)  0.2≤Cosφ<0.5
Active energy| 0.000Wh~9999.9MWh| Min resolution 0.001Wh| ±(1%+3dgt) Cosφ≥0.8
---|---|---|---
±(1.5%+10dgt)0.2≤Cosφ<0.8
Reactive energy, inductive or capacitive| 0.000VARh~9999.9MVARh| Min resolution 0.001VARh| ±(1%+3dgt)Sinφ≥0.5
±(1.5%+10dgt)0.2≤Sinφ<0.5
Papparent energy| 0.000VAh~ 9999.9MVAh| Min resolution 0.001VAh| ±(1%+3dgt)
Phase angle| -179°~ 180°| 1°| ±(2°)
Tanφ (VA≥50VA)| -32.76~ 32.76| Min resolution 0.001| φ:±(1°)
The phase shift of power factor (PDF)| -1.000~ 1.000| 0.001| φ:±(1°)
Harmonic ratio (order 1 to 50) (Vrms >50V)| 0.0%~ 99.9%| 0.1%| ±(1%+5dgt)
Harmonic angle (Vrms >50V)| -179°~ 180°| 1°| ±(3°) harmonics of order 1 to 25
±(10°) harmonics of order 26 to 50
Total harmonic ratio (THD or THD-F)≤50| 0.0%~ 99.9%| 0.1%| ±(1%+5dgt)
Distortion factor (DF or THD-R)≤50| 0.0%~ 99.9%| 0.1%| ±(1%+10dgt)
Transformer K factor| 1.00~ 99.99| 0.01| ±(5%)
3 phases unbalance| 0.0%~ 100%| 0.1%| ±(1%)
---|---|---|---

16.2.4. Current sensor characteristics (after linearization)
Sensor errors are offset by a typical correction inside the device. This typical correction, applied to the phase and amplitude, depends on the type of sensor connected and detected automatically) and the gain in the current acquisition channel used.

Type of current sensor| True RMS current| Max error of true RMS current| Max error of phase angleφ
---|---|---|---
008B current clamp| 10mA~ 99mA| ±(1%+3dgt)| ±(1.5°), Arms≥20mA
100mA~ 10.0A| ±(1%+3dgt)| ±(1°)

040B current clamp

| 0.10A~ 0.99A| ±(1%+3dgt)| ±(1.5°)
1.00A~ 100A| ±(1%+3dgt)| ±(1°)

068B current clamp

| 1.0A~ 9.9A| ±(2%+3dgt)| ±(3°)
10.0A~ 1000A| ±(2%+3dgt)| ±(2°)
Optional transformer| Instrument input current
1mA~ 500mA| The selected transformer error:±1%| The selected transformer error:±(1°)

APPENDICES

17.1. Mathematic formulae
17.1.1. Network frequency and sampling
Sampling is controlled by (locked to) the network frequency so as to deliver 256 samples per cycle from 40 Hz to 70 Hz. This locking is essential for the calculations of reactive power, unbalance, and harmonic ratio and angles.
The frequency is measured by analyzing ten consecutive positive-going zero crossings in the first voltage channel (V1) or first current channel (I1) after digital low-pass filtering and digital suppression of the DC component.
The time of the zero crossing is determined precisely by linear interpolation between two samples to achieve a resolution better than 0.002%.
The signals are acquired using a 16-bit converter and (for current acquisition) dynamic gain switches.

17.1.2. RMS values of half-cycle voltage and current (excluding neutral)
Half-cycle RMS phase-to-neutral voltage of phase (i+1)

Half-cycle RMS phase-to-phase voltage of phase (i+1)

Half-cycle RMS current of phase (i+1)

Note: these values are calculated for each half-cycle so as not to miss any fault. NechDemPer is the number of samples in the half cycle.
17.1.3. Minimum and maximum half-cycle RMS values (excluding neutral)

Note: The duration of the evaluation is left to the user’s discretion (reset by pressing the   or key).
17.1.4. Short-term flicker (excluding neutral)
A method based on the IEC 61000-4-15 standard.
The input values are half-cycle phase-to-neutral voltages. The value is updated every 10 minutes.
17.1.5. Peak values (voltage and current)
i = 3 ⇔ neutral(except Upp and Upm)

UNI T UT285C Power Quality Analyzer fig3

Note: NechPer is the number of samples in the half cycle.
17.1.7. RMS value (voltage and current)
Note: NechSec is the number of samples in the second.

17.1.8. Unbalances (voltage and current)
These are calculated from the filtered RMS vector values (over one second) VFrms and AFrms (ideally the fundamental vectors of the signals).

17.1.9. Harmonic calculations (excluding neutral)
These calculations are carried out by FFT (16 bits), 1024 points over four cycles, with a rectangular window (see IEC 1000-4-7). From the real parts bk and the imaginary parts ak, the harmonic factor is calculated for each order and for each phase (Vharm[3][51], Uharm[3][51], and Aharm[3][51]) with respect to the fundamental and the angles Vph[3] [51], Uph[3][51], and Aph[3][51] with respect to the fundamental.
This calculation is carried out according to the following principle:

UNI T UT285C Power Quality Analyzer fig6

Fs: is the sampled signal at the fundamental frequency.
Co : Co: is the DC component.
K: is the number of the frequency spectrum (the order of the harmonic component is

17.1.10. Harmonic distortions (excluding neutral)
Two global values giving the relative quantity of harmonics are calculated: the THD as a proportion of the fundamental (“THD-F”) and the DF as a proportion of the RMS value (“THD-R”). UNI T UT285C Power Quality Analyzer
fig8

Voltage harmonic distortion multiplied by current harmonic distortion equals apparent power harmonic ratio (VAharm[3][51]), voltage harmonic angle minus current harmonic  angle equals power harmonic angle (VAph[3][51])
17.1.11. K factor

17.1.12. Sequence harmonics
Negative-sequence harmonics

UNI T UT285C Power Quality Analyzer harmonicsUNI T UT285C Power Quality Analyzer fig9

17.1.13. LS powers (excluding neutral)
UNI T UT285C Power Quality Analyzer LS powers Reactive powers are calculated using the filtered signals (without harmonics) in accordance with EDF (French national electricity company) rules or from the apparent and active powers (with harmonics). The choice of calculation is left up to the user.
Total active power.

17.1.14. Power ratios

Tangent.

UNI T UT285C Power Quality Analyzer Tangent

17.1.15. Energies (excluding neutral)
◆Consumed energies (w[i] ≥ 0)
Consumed active energy of phase (i+1)

UNI T UT285C Power Quality Analyzer Energies

◆generated energies (w[i] < 0)

UNI T UT285C Power Quality Analyzer Tangent2
17.2. Hysteresis
Hysteresis is a screening principle that is often used after the detection of a threshold stage in Alarm mode (See § 5.10) and in Inrush current mode (see § 6.3). A correct hysteresis setting avoids repeated changes of state when the measurement oscillates about the threshold.

17.2.1. Surge detection
With a hysteresis of 2%, for example, the return level for surge detection is equal to (100% – 2%) or 98% of the reference voltage threshold.

17.2.2. Undervoltage or blackout detection
With a hysteresis of 2%, for example, the return level for Undervoltage detection is equal to (100% + 2%) or 102% of the Reef voltage threshold.UNI
T UT285C Power Quality Analyzer blackout

17.3. Four-quadrant diagram
UNI T UT285C Power Quality Analyzer diagram 17.4. Mechanism for triggering transient captures
The sampling rate is a constant of 256 samples per cycle. When a transient capture is started, each sample is compared to the sample from the preceding cycle. The preceding cycle defines the mid-point of the trigger envelope and is used as a reference. As soon as a sample is outside the envelope, the triggering event occurs; the representation of the transient is then captured by the device. The cycle preceding the event and the three following cycles are saved to memory. UNI T UT285C Power Quality Analyzer
captures

17.5. Capture conditions in inrush current mode
Reminder: The capture depends on a triggering (start) event and a stop event. If a capture ends with a stop event or if the recording memory of the device is full, the capture stops automatically.
The capture stop threshold is calculated as follows:
[Stop threshold [A]] = [Start threshold [A]] × (100 – [stop hysteresis [%]]) ÷ 100
Here are the conditions for triggering and stopping captures:

Triggering
channel| Triggering and stop conditions
---|---
Al| Triggering condition <=> [Al half-cycle RMS value] > [Triggering threshold] Stop condition <=> [Al half-cycle RMS value] < [Stop threshold]
A2| Triggering condition <=> [A2 half-cycle RMS value] > [Triggering threshold] Stop condition <=> [A2 half-cycle RMS value] < [Stop threshold]
A3| Triggering condition <=> [A3 half-cycle RMS value] > [Triggering threshold] Stop condition <=> [A3 half-cycle RMS value] < [Stop threshold]
3A| Triggering condition <=> [[the half-cycle RMS value of one current channel]> [Triggering threshold] Stop condition <=> [the half-cycle RMS values of all current channels] < [Stop threshold]

 MAINTENANCE

18.1. Important recommendation
For maintenance, use only the spare parts specified. The manufacturer cannot be held liable for any accident that occurs following a repair not performed by its customer service department or by an approved repairer.
18.2. Recharging the battery
The battery charge is managed by the device when connected to the AC network via the mains power unit supplied.
★ For safety reasons and to ensure the correct operation of the charger, the storage battery must be replaced with power off.
★ Do not throw the battery into a fire.
★ Do not expose the battery to a temperature in excess of 75°C.
★ Do not short-circuit the terminals of the battery.
★ When the battery is fully recharged, please remove the power adapter(if do not use an external power supply).
18.3. Replacing the battery
For safety reasons, advice that replaces the battery only with the original model
To replace the battery, proceed as follows:
★ To eliminate all risks of electric shock, disconnect the power supply cord and connected devices.
★ Turn the device over.
★ Use a cross screwdriver to unscrew the two quarter-turn screws on the back of the housing. Then open the battery cover.
★ Gently remove the old battery, and replace a new original battery (To avoid damaging the battery connection, do not pull on the wires).
★ Put the battery compartment cover back in place and screw the 2 quarter-turn screws back in.
★ Reboot the device to confirm.
Note: If the battery is disconnected, it must then be fully recharged, even if it is not replaced, so that the device will know the battery charge condition (this information is lost when the battery is disconnected.UNI T
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