Wiring A Status Switch - Carrier RTU Open v3 Installation And Startup Manual

To wire an enthalpy switch (differential) to the controller
Wiring diagram for optional enthalpy sensor mounted in the return air for differential enthalpy:

Wiring a status switch

Filter - Part #CRSTATUS005A00 or field-supplied
Fan status - Part #CRSTATUS005A00 or field-supplied
Filter and/or fan status switches may be installed to provide a Dirty Filter indication or Fan Running status.
Wiring specifications
Cable from sensor to controller:
Maximum length:
RTU Open v3
Installation and Start-up Guide
If <100 ft (30.5 meters)
If >100 ft (30.5 meters)
500 feet (152 meters)
37
Installing the RTU Open
22 AWG, unshielded
22 AWG, shielded
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