ACI I0000825 Remote Probe Humidity Instruction Manual

June 3, 2024
ACI

ACI I0000825 Remote Probe Humidity

GENERAL INFORMATION

The A/RH Remote Probe Series Sensor is a Relative Humidity transmitter that can be powered with either an AC or DC supply voltage. The RH Remote Probe transmitter is eld selectable with a 4-20 mA, 0-5 VDC, or 0-10 VDC output signal that is equivalent to 0 to 100% RH. This sensor is designed for use with electronic controllers in commercial heating and cooling building management systems. All units are shipped from the factory set up for a 4-20 mA output. The transmitter can also include an optional temperature sensor for monitoring the space temperature.

For optimal readings, follow these tips:

  • Do not install on external walls.
  • Avoid air registers, diffusers, vents, and windows.
  • Eliminate and seal all wall and conduit penetrations. Air migration from wall cavities may alter temperature readings.
  • Do not install near heat sources. eg: lamps, radiators, direct sunlight, copiers, chimney walls, walls concealing hot-water pipes.

MOUNTING INSTRUCTIONS

Remote Probe sensors may be mounted using a 3/4” mounting clip(not supplied) on walls or with cable ties. The sensor should be mounted in an area where air circulation is well mixed and not blocked by obstructions.

The RH Remote Probe includes a Black Rubber Cap that fits over the sensor filter. This cap should be placed on the sensor filter during wet/wash down processes. The cap must be removed for normal operation.

TRANSMITTER MOUNTING
Attach the base directly to the wall by first drilling pilot holes for the mounting screws. Alternatively, you may refer to the dimensions listed in FIGURE 1 (top) to measure out.

ENCLOSURE DIMENSIONS

ACI-I0000825-Remote-Probe-Humidity-fig-1

SENSOR MOUNTING
To fix the probe on a wall, ACI recommends a height of 48-60” (1.2-1.5 m) off the ground and at least 1.5’ (0.5 m) from the adjacent wall. Slide the sensor probe through the mounting clip(not supplied) – see FIGURE 2 (middle). Drill a screw through the socket and tighten to the wall. Refer to Wiring Instructions (p. 2-4) to make necessary connections.

MOUNTED ASSEMBLY

ACI-I0000825-Remote-Probe-Humidity-fig-2

WIRING INSTRUCTIONS

PRECAUTIONS

  • Remove power before wiring. Never connect or disconnect wiring with power applied.
  • Shielding – When using a shielded cable, ground the shield at the Transmitter ONLY. Do NOT ground the shield at the controller. Grounding both ends can cause a ground loop. The shield needs to be terminated into the Com terminal.
  • Do not run the temperature sensor wiring in any conduit with line voltage (24/120/230 VAC) if utilizing resistance temperature signal.
  • It is recommended you use an isolatedUL-listed class 2 transformer when powering the unit with 24 VAC. Failure to wire the devices with the correct polarity when sharing transformers may result in damage to any device powered by the shared   transformer.
  • If the 24 VDC or 24VAC power is shared with devices that have coils such as relays, solenoids, or other inductors, each coil must have an MOV, DC/AC Transorb, Transient Voltage Suppressor (ACI Part: 142583), or diode placed across the coil or inductor. The cathode, or banded side of the DC Transorb or diode, connects to the positive side of the power supply. Without these snubbers, coils produce very large voltage spikes when de-energizing that can cause malfunction or destruction of electronic circuits.

ROUND PCB

RELATIVE HUMIDITY WIRING INSTRUCTIONS

The PG11 cord grip cap is shipped loosely tightened. Make sure that is loose when you open the cover. This is the cord grip that the remote sensor goes to. Open the cover of the enclosure. ACI recommends 16 to 26 AWG twisted pair wires or shielded cable for all transmitters. Twisted pair may be used for 2-wire current output transmitters or 3-wire for voltage output. Refer to FIGURE 4 (below) or wiring diagrams.

TEMPERATURE WIRING INSTRUCTIONS
ACI recommends 16 to 26 AWG twisted pair wires or shielded cable for all temperature sensors. ACI recommends a separate cable be pulled for Temperature signal only. Temperature Signal wiring must be run separate from low and high voltage wires (24/120/230VAC). All ACI thermistors and RTD temperature sensors are both non-polarity and non-position sensitive

OUTPUT SIGNALS

2 WIRE CURRENT OUTPUT SIGNAL

3 WIRE CURRENT OUTPUT SIGNAL

ACI-I0000825-Remote-Probe-Humidity-fig-5

VOLTAGE OUTPUT SIGNAL

ACI-I0000825-Remote-Probe-Humidity-fig-6

All thermistor type units are supplied with (2)flying lead wires, and all RTD’s are supplied with (2) or (3) flying lead wires – see FIGURE 5 (above) . The number of wires needed depends on the application. Connect thermistor/RTD wire leads to controller analog input wires using wire nuts, terminal blocks, or crimp style connectors. All wiring must comply with local and National Electric Codes. After wiring, attach the cover to the enclosure

Note: Shielding – When using a shielded cable, ground the shield at the Transmitter ONLY. Do NOT ground the shield at the controller. Grounding both ends can cause a ground loop. The shield needs to be terminated into the Com terminal.

Note: If the controller requires a (2) wire input for a RTD, connect the (2) common wires (same color) together. If the controller requires (3) wires, use (3) individual wires – see FIGURE 5 (above).

OUTPUT SIGNALS

Switches 6, 7, and 8 are used to set the RH output signal. Refer to FIGURE 6 (below) for switch settings.

HUMIDITY REVERSE ACTING OUTPUT

The output is direct acting and can be changed to reverse acting mode. The output range stays the same  but the corresponding RH value is opposite

TEMPERATURE WIRING

2-WIRE THERMISTOR or RTD WIRING

3-WIRE RTD WIRING

OUTPUT SELECTION SWICHES

HUMIDITY REVERSE ACTING OUTPUT
The output is direct acting and can be changed to reverse acting mode. The output range stays the same but the corresponding RH value is opposite

Examples:

  • Direct Acting (DA) Reverse Acting (RA)
  • 0-10 V output mode, 0-10 V output mode,
  • 0 V = 0% RH and 10 V = 100% RH 0 V = 100% and 10 V = 0%

To change the transmitter to reverse acting or back to direct acting, set switch 4 to ON to put the unit in setup mode. After switch 4 is on, turning switch 2 to ON will put the unit in direct/reverse acting mode. When switch 2 is set to ON, the output can be used to show if the unit is in direct or reverse acting mode. For direct acting, the output will be 1 V for 0-5 V, 2 V for 0-10 V, and 7.2 mA for 4-20 mA. For reverse acting the output will be 4 V for 0-5 V, 8 V for 0-10 V, and 16.8 mA for 4-20 mA. With switches 2 and 4 ON, each time switch 5 is set to ON the output will change to reverse acting or direct acting. To reset the unit to the default setting, toggle both switches 5 and 6 ON then OFF while both switches 2 and 4 are ON. When all calibration is completed, remember to place the switches back into the positions that correspond to the output needed as shown in FIGURE 6 (p. 3).

RH CALIBRATION INSTRUCTIONS

The dipswitch allows the user to calibrate the sensor through the software. Setting switch 4 ON will put the transmitter into setup mode allowing the increment and decrement to work. Once in setup mode, the output will change to 50% (2.5 V for 0-5 V or 5 V for 0-10 V). Each increment or decrement step will cause the output to change by 0.1 V for 0-5 V or 0.2 V for 0-10 V in setup mode. This can be used to show the user how far offset the transmitter is. To see the starting point again set switch 1 ON.  This will show the 50% output again. When the unit is out of setup mode the output will go back to RH output. The maximum offset is 10%. There can be a total of 20 increments.

Increment RH Output
This will shift the RH output linearly up in 0.5% steps. Switch 4 must be set to ON first. After switch 4 is on, each time switch 5 is set ON the RH output will increase by 0.5%. The increase goes into effect each time switch 5 is set to ON.

Decrement RH Output
This will shift the RH output linearly down in 0.5% steps. Switch 4 must be set to ON first. After switch 4 is on, each time switch 6 is set ON the RH output will decrease by 0.5%. The decrease goes into effect each time switch 6 is set to ON.

Reset RH Output
This will reset the RH output back to the original calibration. Switch 4 must be set to ON first. After switch 4 is on, toggle switches 5 and 6 ON then OFF. After 5 and 6 are OFF slide switch 4 OFF. When all calibration is completed, remember to place the switches back into the positions that correspond to the output needed as shown in FIGURE 6 (p. 3).

TEST INSTRUCTIONS

Test mode will make the transmitter output a fixed 0%, 50%, or 100% value. The sensor will not affect the transmitter output. This is used for troubleshooting or testing only. Switches 1, 2, and 3 are used for test mode. The output will be a fixed 0%, 50%, or 100% signal that corresponds to the output selected with switches 6, 7, and 8. Refer to FIGURE 7 (right) for switch settings.

TEST SELECTION SWITCHES

RH CONVERSION FORMULAS

  4-20 mA 0-5 VDC 0-10 VDC
Formula: ([mA signal] -4) / 0.16 = percent RH [VDC signal] / 0.05 =
percent RH [VDC signal] / 0.10 = percent RH
Example: 12 mA output signal

(12 – 4) / 0.16 = 50% RH

| 1.25 vdc output signal

1.25 / 0.05 = 25% RH

| 7.50 vdc output signal

7.50 / 0.10 = 75% RH

PRODUCT SPECIFICATIONS

  SENSOR SPECIFIC
RELATIVE HUMIDITY RH Supply Voltage:

(Reverse Polarity Protected)

| 4-20 mA: 250 O Load: 15 – 40 VDC / 18 – 28 VAC | 500 O Load: 18 – 40 VDC / 18 – 28 VAC

0-5 VDC: 12 – 40 VDC / 18 – 28 VAC | 0-10 VDC: 18 – 40 VDC / 18 – 28 VAC

RH Supply Current (VA):| Voltage Output: 8 mA max (0.32 VA) | Current Output: 24 mA max (0.83 VA)
RH Output Load Resistance:| 4-20 mA: 700 O maximum | 0-5 VDC or 0-10 VDC: 4K O Minimum
RH Output Signal:| 2-wire: 4 – 20 mA (Default) | 3-wire: 0-5 or 0-10 VDC and 4 – 20 mA (Field Selectable)
RH Accuracy @ 77°F (25°C):| +/- 1% over 20% RH Range between 20 to 90% | +/- 2%, 3%, or 5% from 10 to 95%
RH Measurement Range:| 0-100%
Operating RH Range:| 0 to 95% RH, non-condensing (Conformally Coated PCB’s)
Operating Temperature Range:| -13 to 140 °F (-25 to 60 °C)
Storage Temperature Range:| -13 to 149 °F (-25 to 65 °C)
RH Stability | Repeatability | Sensitivity:| Less than 2% drift / 5 years | 0.5% RH | 0.1% RH
RH Response Time (T63):| 20 Seconds Typical
RH Sensor Type:| Capacitive with Hydrophobic Filter
RH Transmitter Stabilization Time:| 30 Minutes (Recommended time before doing accuracy verification)
RH Connections | Wire Size:| Screw Terminal Blocks (Polarity Sensitive) | 16 (1.31 mm²) to 26 AWG (0.129 mm²)
RH Terminal Block Torque Rating:| 4.43 to 5.31 lb-in (0.5 to 0.6 Nm)
Minimum Cable Bend Radius:| 1.92” (48.77 mm) or 10x the Cable Diameter
Cable Ratings | Cable Jacket Material:| UL (CMP, CL3P, FPLP); CSA(CMP, FT6), Plenum Rated | Polyvinyl Chloride (PVC)
Cable Operating Temperature Range:| 32 to 167 °F (0 to 75 °C)
Enclosure Specifications: (Material,

Flammability, Temp., NEMA/IP Ratings)

| “-EH” Enclosure: ABS Plastic; UL94-V0; -40 to 140 °F (-40 to 60 °C)
Sensing Tube Material:| 304 Series Stainless Steel
Filter Material:| 304 Series Stainless Steel
Probe Dimensions (Length x Diameter):| 5.12” (130.10 mm) x 0.750” (19.05 mm)
 | SENSOR NON-SPECIFIC
TEMPERATURE| Lead Wire Length| 14” (35.6 cm) | 22 AWG (0.65 mm)
Insulation Rating| Etched Teflon (PTFE) Colored Leads | Mil Spec 1678/4 Type E
PLATINUM
Sensor Output @ 0 °C (32 °F):| A/100: 100 O nominal| A/1K: 1 KO nominal
Accuracy:| +/- 0.06% Class A (Tolerance Formula: +/- °C = (0.15 °C + (0.002 * |t|))

where |t| is the absolute value of Temperature above or below 0 °C in °C)

@ -40 °C (-40 °F): +/- 0.23ºC (+/- 0.414ºF)

@ 0 °C (32 °F): +/- 0.15 °C (+/- 0.27 °F)

| @ 60 °C (140 °F): +/- 0.27 °C (+/- 0.49 °F)

WARRANTY

The ACI Remote Probe Series RH sensors are covered by ACI’s Five (5) Year Limited Warranty, which is located in the front of ACI’S SENSORS & TRANSMITTERS CATALOG or can be found on ACI’s website: www.workaci.com.

W.E.E.E. DIRECTIVE
At the end of their useful life the packaging and product should be disposed of via a suitable recycling centre. Do not dispose of with household waste. Do not burn

TROUBLESHOOTING

HUMIDITY READING PROBLEM SOLUTION(S)
No Reading •     Check that you have the correct supply voltage at

the power terminal blocks.

•     Check that wiring configurations and all DIP switch settings are as in

FIGURE 5 (p. 3) and 7 (p. 4).

•     Verify that the terminal screws are all connected tightly and that all of the wires are firmly in place.

Erratic readings| •     Verify that all of the wires are terminated properly.

•     Make sure that there is no condensation on the board.

•     Check that the input power is clean. In areas of high RF interference or noise, shielded cable may be necessary to stabilize signal.

Inaccurate readings| •     Verify proper mounting location to confirm no external factors (see

mounting locations above).

•     Check the output (voltage or current) against a highly accurate recently calibrated secondary reference. Measue RH at the location of the sensor using the secondary reference, then calculate the RH percentage using the RH CONVERSION FORMULAS (p. 4). Compare the calculated output to reference.

•     If the sensor is brand new, leave the sensor powered for at least 30

minutes to stabilize.

•     If you suspect that the transmitter is not reading within the specified tolerance, please contact ACI for further assistance.

TEMPERATURE (Optional) PROBLEM| SOLUTION(S)
Sensor reading is incorrect| •     Verify sensor wiring to controller is not damaged and has continuity

•     Verify sensor or wires are not shorted together

•     Verify controller is setup for correct sensor curve

•     Disconnect sensor wires, and take a resistance (ohm) reading with a multimeter

•     Compare the resistance reading to the Temperature Vs Resistance

Curves online: http://www.workaci.com/content/thermistor-curves- 0

•     Verify proper mounting location to confirm no external factors

Sensor reads infinity/very high resistance| •     Sensor or wires are open
Sensor reads low resistance| •     Sensor or wires are shorted together
Erratic readings| •     Bad wire connections

Automation Components, Inc.
2305 Pleasant View Road | Middleton, WI 53562 Phone: 1-888-967-5224 | Website: workaci.com

Version : 3.0 I0000825

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