Issue:
Quality - K42 relay on VFD has failed.
This relay is used on Danfoss Variable Frequency Drive assemblies when the unit is ordered with a VFD on the supply fan, exhaust fan and/or variable speed compressors.
Problem:
Whenever you discover that there are nuisance supply or exhaust fan failures or compressor trip diagnostics on the variable speed compressor's circuit the culprit is generally traced back to a failed K42 relay. The issue generally found with the K42 relay is that the coil is energized but the contacts do not close.
Resolution:
Replace the K42 relay. A vendor issue causing this problem was resolved in mid 2007. Production units (new drives) are seeing this issue on drives built between November 2006 and up until approximately November 2007 (due to a lag in production of new drives versus replacement parts).
01/20 Update:
Due to ongoing issues with the K42 relay, the GE manufactured relay has been replaced by one manufactured by ABB (Jan 2020). The part number for the replacement ABB relay is RLY03902.
Notes:
Contacts fail sometimes on startup, sometimes after a few months of operation. The NO contacts will not close.
Facts:
- VOYAGER 27.5-50
- Intellipak I
- Intellipak II
- The relay tends to fail on or close to startup.
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.