Contactor/Drive Fail
This diagnostic indicates that compressor proving input at the SCM/MCM was closed when the unit was NOT actively calling for compressor operation. This generally is a sign of a faulty contactor, the compressor proving NO auxiliary switch is sticking or compressor proving wires are mistakenly wired to the NC contacts. This alarm can also be generated if a service technician manually engages the compressor contactor while troubleshooting.
Example: IPAK 1 with MCM
On units with a Variable Speed Compressor it will be an indication that the K42 relay is faulty or compressor proving is mis-wired to the NC terminals 4,6 terminals.
Refer to your unit's schematic for your specific wire locations.
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.