RTRM/RTOM - Temperature Inputs Outdoor Air Sensor, Discharge Air Sensor, and Coil Temperature Sensor
Terminals to Read Voltage
Outdoor Air Sensor — RTRM J8-2, J8-1
Discharge Air Sensor — RTOM J4-5, J4-4
Coil Temperature Sensor 1 —RTRM J2-3, J2-4
Coil Temperature Sensor 2 —RTRM J9-2, J9-1
Note: These are RTRM, RTOM inputs only. Economizer inputs (MAT, RAS, OHS, RHS, CO2) are in the ReliaTel™ Economizer inputs section.
Read DC voltage with the sensor attached. If voltage does not appear to be correct, read the resistance of the circuit, then the sensor itself, to see if a problem exists in the sensor or the wiring. With the sensor not attached there should be 5.00 VDC at the terminals listed above.
Service Tips
The second sensor terminal listed above is common. All common terminals are grounded, therefore one voltmeter lead can be attached to ground for voltage tests. To check for induced voltage, read AC voltage to ground from each sensor wire. Should be less than 1 VAC.
Problems to Look for
• Mis-wire / short / open
• Excessive resistance in the circuit (corroded or loose
connection)
• Sensor inaccurate (should be +- 2F of chart)
• Moisture in the sensor (becomes accurate when dry)
• Induced voltage (high voltage wires in same
conduit
Refer to table 85. Temperature Inputs page 113 - 115 of RT-SVD03M-EN
*Please refer to the latest available literature when available.* - Click the link below:
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.