blowing fuse after awhile

[RUSS13]

Customer has Trane heat pump that keeps blowing 5A fuse after 1-14 days.It only goes in first stage heat.I had them run emergency heat to try to blow fuse but didnt happen.

[toocoolforschool]

Voltage spikes may cause this, or their has to be a short somewhere in the 24volt circuit, you have to chase it down, inspect every wire.

[fliks]

You could check amp draw also. I recently had one that was exactly like your situation. It wpuld work fine then kick a fuse. Checked tstat wire for continuity to ground and to each other. Got a quick reading a couple of times but went away. I had a good meter and set on a sensitive setting so I just thought it was picking up me touching the leads. Finally changed wire and that fixed it. Pulled some of the old wire and the insulation was brittle and the wire was green and corroded.

[HighlandThunder]

You could check amp draw also. I recently had one that was exactly like your situation. It wpuld work fine then kick a fuse. Checked tstat wire for continuity to ground and to each other. Got a quick reading a couple of times but went away. I had a good meter and set on a sensitive setting so I just thought it was picking up me touching the leads. Finally changed wire and that fixed it. Pulled some of the old wire and the insulation was brittle and the wire was green and corroded.

+1

A couple of trouble spots to check for control wire breaches are where the control wire goes through the wall with the refrigerant line set and inside the compressor compartment. I can't tell you how many times I have repaired spots in the reversing valve wire or pressure switch wire where it had been resting on one of the copper pipes and time and vibration wore through the insulation creating a short to ground.

-Brian

[uniservice]

+1

A couple of trouble spots to check for control wire breaches are where the control wire goes through the wall with the refrigerant line set and inside the compressor compartment. I can't tell you how many times I have repaired spots in the reversing valve wire or pressure switch wire where it had been resting on one of the copper pipes and time and vibration wore through the insulation creating a short to ground.

-Brian

+1