HK INSTRUMENTS DPI Series Differential Pressure Switches Installation Guide
- October 30, 2023
- HK INSTRUMENTS
Table of Contents
DPI Series Differential Pressure Switches
Installation Guide
DIFFERENTIAL PRESSURE SWITCHES
DPI Series
INTRODUCTION
Thank you for choosing an HK Instruments DPI series electronic differential
pressure switch. The DPI series is intended for use in commercial
environments. It combines the advantages of an electronic differential
pressure switch (on-off relay) and a multi-functional differential pressure
transmitter to meet your application requirements. The DPI series is comprised
of the DPI±500 with bi-directional measurement ranges from ±100 to ±500 Pa
and the DPI2500 with measurement ranges from 100 to 2500 Pa.
All DPI series devices include one relay, display, manual pushbutton zero
point calibration and span point calibration. Optional features include a
second relay and autozero calibration.
APPLICATIONS
DPI series devices are commonly used in HVAC/R systems for:
- fan, blower and filter monitoring
- staircase pressure monitoring and alarm
- pressure monitoring in cleanrooms
- boiler pressure monitoring and alarm
WARNING
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READ THESE INSTRUCTIONS CAREFULLY BEFORE ATTEMPTING TO INSTALL, OPERATE OR SERVICE THIS DEVICE.
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Failure to observe safety information and comply with instructions can result in PERSONAL INJURY, DEATH AND/OR PROPERTY DAMAGE.
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To avoid electrical shock or damage to equipment, disconnect power before installing or servicing and use only wiring with insulation rated for full device operating voltage.
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To avoid potential fire and/or explosion do not use in potentially flammable or explosive atmospheres.
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Retain these instructions for future reference.
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This product, when installed, will be part of an engineered system whose specifications and performance characteristics are not designed or controlled by HK Instruments. Review applications and national and local codes to assure that the installation will be functional and safe. Use only experienced and knowledgeable technicians to install this device.
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Fuse at load supply(normally6A,10A,16A)does not always limit therelayoutputloadcurrentto6A.RelayMaximumLoad(250Vx 6 A res.)
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Add an external fuse to relay common connector. Use a time-lag fuse(max6A)thatisinaccordancewiththestandardIEC60127-2.
The product doesn’t have an internal fuse for the relay.
CAUTION: The product may only be connected to overvoltage category II electricity network according to IEC 60664-1.
SPECIFICATIONS
Performance
Accuracy: ±1.5 % (±0.7 %) %FS from highest pressure range (including:
general accuracy, temperature drift, linearity, hysteresis and repetition
error)
Can be achieved with span point calibration
Long term stability: Typical 1 year
With autozero: ±1 Pa
Without autozero: ±8 Pa
Thermal effects:
Temperature compensated across the full spectrum of capability
Overpressure:
Proof pressure: 25 kPa
Burst pressure : 30 kPa
Zero point calibration : Automatic with autozero (-AZ) circuit or Manual
via menu
Response time: 0.5–10 s, selectable via menu
Technical Specifications
Media compatibility:
Dry air or non-aggressive gases
Measuring units:
Pa, kPa, mimic, iNWS, mbar selectable via menu
Measuring element: Piezo resistive
Environment:
Operating Temperature:
With out auto zero:-10…50°C
With auto zero:-5…50°C
Storage temperature: -20…70 °C
Humidity: 0 to 95 % rah, non condensing
Physical
Dimensions:
Case: 89 x 86.5 x 37.1 mm
Weight: 150 g
Mounting:
Case: 2 each 4.3 mm holes
Lid: 2 each 4.3 mm holes
Materials:
Case: ABS
Lid: PC
Duct connectors: ABS
Tubing: PVC
Protection standard: IP54
Touch sensitive buttons on the lid: Menu, Back, OK, down arrow, up arrow
Display:
3 1/2 digit LCD backlit display
Size: 46.0 W x 14.5 H mm
Electrical connections:
n/out:
Terminal block (24 V, GND, 0–10 V)
Wire:0.2–1.5mm² (16–24AWG)
Relay 1:
Terminal block (NC, COM, NO)
Wire:0.2–1.5mm² (16–24AWG)
Relay 2:
Terminal block (NC, COM, NO)
Wire:0.2–1.5mm² (16–24AWG)
Cable entries:
Strain relief: M16 & M20
Knockout : 16 mm
Knockout : 20 mm
Pressure fittings:
5.2 mm barbed brass
+ High pressure
− Low pressure
Electrical
Circuit: 3-wire (24 V, GND, 0–10 V)
Input:
Withoutautozero:21–35VDC/24VAC,±10%
Withautozero:24VACorVDC,±10%
Output:
Analog: 0–10 V
Relay 1: 250 VAC / 30 VDC / 6 A
Relay 2: 250 VAC / 30 VDC / 6 A
Adjustable switching point and hysteresis
Zero/Span output calibrated within ±0.025 V
Resistance minimum: 1 kΩ
Current consumption:
35 mA + relays (7 mA each) + AZ circuit (20 mA)
+ 0–10 V output (10 mA)
Conformance
Meets requirements for:
| CE:| UKCA:
---|---|---
EMC:| 2014/30/EU| S.I.2016/1091
RoHS:| 2011/65/EU| S.I.2012/3032
LVD/EESR:| 2014/35/EU| S.I.2016/1101
WEEE: :| 2012/19/EU| S.I.2013/3113
SCHEMATICS
DIMENSIONAL DRAWINGS
INSTALLATION
- Mount the device in the desired location (see step 1).
- Open the lid and route the cable(s)through the strain relief(s)and connect the wires to the terminal block(s) (see step 2).
- The device is now ready for configuration.
WARNING! Apply power only after the device is properly wired.
STEP 1: MOUNTING THE DEVICE
- Select the mounting location (duct, wall, panel).
- Use the device as a template and mark the screw holes.
- Mount with appropriate screws.
STEP 2: WIRING DIAGRAMS
For CE compliance, a properly grounded shielding cable is required.
- Unscrew the strain relief and route the cable(s). Use separate strain relief for the 0–10 V output cable and the relay cable(s).
- Connect the wires as shown in figure 2a and 2b.
- Tighten the strain relief.
STEP 3: CONFIGURATION
- Select the desired measurement unit.
- Select the desired measurement range.
- Select the desired response time.
- Configure the relay(s).
- Zero the device.
- Calibrate the span point.
- Connect the pressure tubes. Connect positive pressure to port labeled “+” and negative pressure to port “-“.
The device is now ready to be used.
With the button you can enter the menu by pressing the button for 3 seconds.
You can exit the menu without making any changes.
With the button you can return without making changes.
With the button you can open new options or confirm changes and return to
previous display.
With the buttons you can scroll the menus.
STEP 4: ZEROING THE DEVICE
NOTE! Always zero the device before use.
To zero the device two options are available:
- Manual zero point calibration
- Autozero calibration
Does my transmitter have an autozero calibration? See the product label. If it shows-AZ in the model number, then you have the autozero calibration.
- Manual zero point calibration
NOTE: Supply voltage must be connected at least one hour prior to zero point adjustment.
a) Disconnect both pressure tubes from the pressure ports labeled + and -.
b) Push both arrow buttons on top of the lid shortly or go to configuration
menu and select “Zero”.
c) The zeroing of the device will proceed automatically when the green led on
top of the lid turns off and “Zero” text followed by a counter from 3 to 0
seconds appears on the display. The zeroing is complete when the green led
turns on again.
d) Reinstall the pressure tubes ensuring that the High pressure tube is
connected to the port labeled +, and the Low pressure tube is connected to the
port labeled -.
NOTE: The zero point should be calibrated via manual zero point
calibration one hour after installation and at least every 12 months during
normal operations.
- Autozero calibration If the device includes the optional autozero circuit, no action is required.
Autozero calibration (-AZ) is an autozero function in the form of an automatic
zeroing circuit built into the PCB board. The autozero calibration
electronically adjusts the transmitter zero at predetermined time intervals
(every 10 minutes). The function eliminates all output signal drift due to
thermal, electronic or mechanical effects, as well as the need for technicians
to remove high and low pressure tubes when performing initial or periodic
transmitter zero point calibration. The autozero adjustment takes 4 seconds
after which the device returns to its normal measuring mode. During the 4
second adjustment period, the output and display values will freeze to the
latest measured value.
Transmitters equipped with the autozero calibration are virtually maintenance
free.
RECYCLING/DISPOSAL
The parts left over from installation should be recycled according to your local instructions. Decommissioned devices should be taken to a recycling site that specializes in electronic waste.
WARRANTY POLICY
The seller is obligated to provide a warranty of five years for the delivered goods regarding material and manufacturing. The warranty period is considered to start on the delivery date of the product. If a defect in raw materials or a production flaw is found, the seller is obligated, when the product is sent to the seller without delay or before expiration of the warranty, to amend the mistake at his/her discretion either by repairing the defective product or by delivering free of charge to the buyer a new flawless product and sending it to the buyer. Delivery costs for the repair under warranty will be paid by the buyer and the return costs by the seller. The warranty does not comprise damages caused by accident, lightning, flood or other natural phenomenon, normal wear and tear, improper or careless handling, abnormal use, overloading, improper storage, incorrect care or reconstruction, or changes and installation work not done by the seller. The selection of materials for devices prone to corrosion is the buyer’s responsibility, unless otherwise is legally agreed upon. Should the manufacturer alter the structure of the device, the seller is not obligated to make comparable changes to devices already purchased. Appealing for warranty requires that the buyer has correctly fulfilled his/her duties arisen from the delivery and stated in the contract. The seller will give a new warranty for goods that have been replaced or repaired within the warranty, however only to the expiration of the original product’s warranty time. The warranty includes the repair of a defective part or device, or if needed, a new part or device, but not installation or exchange costs. Under no circumstance is the seller liable for damages compensation for indirect damage.
COMPANY WITH MANAGEMENT
SYSTEM CERTIFIED BY DNV
ISO 9001. ISO 14001
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