Defrost Problem Carrier 38ARQ

[wrangoth]

When the unit goes into defrost there are issues happening.

1. The Y circuit cuts out. Compressor goes off.
2. The Outdoor Fan goes off like normal.
3. The Defrost board has an internal relay that has two normally open switches. One for EH and the other for RVS. This relay just starts clicking.
4. It will continue indefinately or until you turn off power and turn back on.

The unit will run fine in Heat Mode or Cool and if you jump R directly to RVS while in Heat Mode it will switch and no problems with losing the Y.

Things we have done.

1. We have replaced the Defrost Board thinking it was bad.
2. The problem was still present. We troubleshooted and decided to try changing the board again thinking maybe we got a bad one.
3. Same thing continued.

Any Idea's?

Wrangoth

[Brian_UK]

Loose connections, poor neutral ?

Check circuit for continuity.

[wrangoth]

There is a relay in the air handler that energizes through the call for RSV. The Y circuit is on a normally open switch and when the relay would energize to open outdoor dampers the problem would occur.

It only would happen when the unit tried to go into defrost. When the unit was in cool it would run fine. Kinda confusing.

We took the Y circuit off the relay and bypassed the relay and outside dampers. Problem went away. So, we the unit is workingj and will go into defrost but the outside air dampers are not working. Will be looking further..... later.

Thanks