Problem
When does a UC400 staged WSHP bring on auxiliary heat?
Solution
Enable Heat pump with aux heating state (Temperature is 1F below setpoint and heat pump cascade capacity is >= 100%) for 10 minutes AND temperature rise is less than 0.5 F in 10 minutes AND auxiliary heat is installed AND auxiliary heat is configured as supplementary.
Disable heat pump with aux heating state (aux heating capacity is equal to 0% for 5 minutes) OR Auxiliary heat is not installed OR auxiliary heat is configured as exclusive. During heat pump aux heating mode, all heat pump stages stay on, fan operates at high speed, and aux heating will be controlled using existing phase 1 temperature control algorithm. If compressors are locked out due to low ambient conditions or locked out the compressor enable bas, then auxiliary heat is turned on without delay when heating is needed.
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.