Carrier RTU Open v3 User Manual

Installing the RTU Open
RTU Open v3 CARRIER CORPORATION ©2019
Installation and Start-up Guide All rights reserved
35
Wiring an enthalpy switch
Outdoor Air - Part #33CSENTHSW
Return air - Part #33CSENTSEN
The 33CSENTHSW is an outdoor air enthalpy switch/receiver. This control determines the suitability of the outdoor
air as a cooling source, based on the heat content of the air. Differential enthalpy control requires installing a
33CSENTSEN enthalpy sensor in the rooftop unit's return air duct.
Wiring specifications
Cable from sensor to controller: If <100 ft (30.5 meters) 22 AWG, unshielded
If >100 ft (30.5 meters) 22 AWG, shielded
Maximum length: 500 feet (152 meters)
To wire an enthalpy switch (outdoor air) to the controller
An enthalpy switch is typically mounted in the outdoor air inlet.
Wiring diagram for a field-installed enthalpy switch:

Carrier RTU Open v3 Specifications

General

Brand	Carrier
Model	RTU Open v3
Category	Controller
Language	English