Emerson 203-5751 User manual

Document Part # 026-4855 Rev 0 Page 1 of 6
©2022 Emerson Digital Cold Chain, Inc. This document may be photocopied for personal use.
Visit our website at www.climate.emerson.com for the latest technical documentation and updates.
Emerson specs a wall-mounted relative humidity (RH) sensor
(P/N 203-5751) and combined RH and temperature sensor
(P/N 203-5752) for use in building control and anti-sweat control
applications using Emerson input boards.
Specifications
INPUT POWER
Voltage Class 2; 12 to 24 Vdc or 24 Vac
AC Voltage Tolerance ±10%
AC Frequency 50/60 Hz
OUTPUT
Voltage Output 0 to 5 V or 0 to 10 V (jumper selectable)
Voltage Min. Load Resistance 5 kΩ
Voltage Min. Sinking Current 0.2 mA
HUMIDITY
RH Element Digitally profiled thin-film capacitive, non-removable
Accuracy 3% (10 to 90% RH, 20 to 30 °C)
Temperature Effect (Outside 20° to 30°C) ≤0.1% RH per °C
Response Time (to 90% change at 20°C) 110 sec
Annual Drift ≤1%
Humidity (RH) and Temperature Sensor
Wall-mounted RH Sensor and
RH/Temperature Sensor
Installation Guide

Page 2 of 6
Document Part # 026-4855 Rev 0
©2022 Emerson Digital Cold Chain, Inc. This document may be photocopied for personal use.
Visit our website at www.climate.emerson.com for the latest technical documentation and updates.
Mounting
1. Mount the backplate on the wall in an appropriate location with the “Install This End Up” label positioned in the upper
right corner.
2. Wire the unit as shown (see Wiring section).
3. Attach the front plate.
Wiring
1. Use Belden #8771 shielded three-conductor cable or equivalent.
2. Connect the RED, BLACK, and WHITE wires to the screw terminals the sensor’s connector as shown in the image below.
Clip the SHIELD wire.
3. Connect the SHIELD and BLACK wires to the 0V terminal of the input board. Connect the WHITE wire to the SIG terminal
of the input board.
4. Connect the RED wire to the +12V power terminal on the input board.
Output Scaling 0 to 100% RH
TEMPERATURE OPTION
Sensor Type Thermistor, 10k Ohm
OPERATING ENVIRONMENT
Operating Temperature 0 to 50 °C (32 to 122 °F)
Operating Humidity 0 to 100% RH non-condensing (Unit will recover from
saturation)
HOUSING
Material ABS plastic with UL V-0 5VB Flame Class
Mounting Holes US and European junction box
AGENCY APPROVAL
*The CE mark indicates RoHS2 compliance. Please refer to the
CE Declaration of Conformity for additional details.
EMC Conformance: Low Voltage Directive 2014/35/EU and EMC
Directive 2014/30/EU.

Page 3 of 6
Document Part # 026-4855 Rev 0
©2022 Emerson Digital Cold Chain, Inc. This document may be photocopied for personal use.
Visit our website at www.climate.emerson.com for the latest technical documentation and updates.
5. Locate the input dip switch for the sensor point, and set to the OFF position (LEFT for MultiFlex, DOWN for 16AI). Refer to
the input board’s user manual for locations of the input dip switches.
*Temperature models only
Operations
Emerson wall-mounted humidity sensors measure the levels of RH and temperature (if equipped) in the air inside a
room. To maintain accurate functionality, keep all pickup vents clear and free of dust, debris, etc.
LEGEND
RTD RTD*
T/RTD RTD/Temperature*
RH Humidity
GND GRND (DC- or AC1 and Output Common)
PWR POWER (DC+ or AC2)

Page 4 of 6
Document Part # 026-4855 Rev 0
©2022 Emerson Digital Cold Chain, Inc. This document may be photocopied for personal use.
Visit our website at www.climate.emerson.com for the latest technical documentation and updates.
Dimensions
Installation
1. Remove the cover by pressing the tab on the bottom of the sensor while pulling outward on the bottom edge of the cover.

Page 5 of 6
Document Part # 026-4855 Rev 0
©2022 Emerson Digital Cold Chain, Inc. This document may be photocopied for personal use.
Visit our website at www.climate.emerson.com for the latest technical documentation and updates.
2. Position the sensor vertically on the wall, 4 . feet (1.5 m) above the floor. Place so that the “Install This End Up” statement
on the board is in the upper right corner.
3. Mount the backplate onto the wall using the screws provided.

This document may be photocopied for personal use.
Visit our website at http://www.climate.emerson.com for the latest technical documentation and updates.
Join Emerson Technical Support on Facebook. http://on.fb.me/WUQRnt
For Technical Support call 833-409-7505 or email ColdC[email protected]
The contents of this publication are presented for informational purposes only and they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or
applicability. Emerson reserves the right to modify the designs or specifications of such products at any time without notice. Responsibility for proper selection, use and maintenance of any product remains solely with the
purchaser and end-user. ©2022 Emerson is a trademark of Emerson Electric Co.
Document Part # 026-4855 Rev 0 Page 6 of 6
4. Wire the backplate.
5. Install the cover and snap into place.