- *LCU Can I wire a thermostat on a UCP Voyager unit?
Process (Steps 1-4 ):
1. Does the unit have a Conventional Thermostat Interface (CTI) board installed? Refer to Image 1. If yes continue to the next step. If no then continue on to step 3.
Image 1. Conventional Thermostat Interface connected to Unitary Control Processor (UCP)
2. Yes, you can wire a 24VAC thermostat to the unit. Refer to wiring Table 1.
Table 1. Conventional Thermostat Interface Board Wiring
| UCP Wiring Connection | Thermostat Wiring Connection |
| LTB-1 | Compressor 1 (Y1) |
| LTB-3 | Heat 2 (W2) |
| LTB-4 | Compressor 2 (Y2) |
| LTB-5 | Heat 1 (W1) |
| LTB-7 | Indoor Fan (G) |
| LTB-13, 14, or 15 | 24VAC Hot |
| LTB-16 | Unit Shut Down Relay (Closed = on, Open = off) |
| LTB-17 | Unit Shut Down Relay (Closed = on, Open = off) |
| LTB-20 | 24VAC Common |
3. No, the unit cannot currently be controlled with a thermostat. Please contact your local Trane Parts Center to obtain a CTI board. Please have your unit serial and model number available.
4. End.
Open the attachment BAYCTHI001CA .PDF for the CTI installation guide.
Open the attachment CTI_23070309.pdf for a CTI wiring diagram.
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.