Thermostat J21 Terminals

Thermostats

Customers occasionally require operation with a conventional thermostat rather than a zone sensor. Non-Trane building controllers typically provide an interface to HVAC equipment based on a conventional thermostat interface. Units applied with this type of controller need to accept conventional thermostat inputs. Conventional thermostat signals represent direct requests for unit functions. This function provides inputs for the thermostat signals and processing to enhance reliability and performance. Compressor protection and reliability enhancement functions (HPC, LPC, minimum On/Off timers, etc.) all operate the same whether applied with zone sensors or a conventional thermostat. Logic is also provided to cause appropriate unit functions when inappropriate thermostat signals are provided. Simultaneous calls for heating and cooling will be ignored, and the fan will be turned on with a call for heating or cooling even if the fan request is not detected. If the thermostat is immediately changed from a heating to a cooling call or vice versa, there will be a delay before the new mode will initiate.

Explanation Table

Two-Stage Cooling Only Example

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.