My AC' Fuse keep blowing every 2-3 days.
AC is 4 years old. Already replaced 3 fuses. AC has disconnect with set of two fuses (35A 250V) in the box on the wall outside, by the AC.
Thermostat's working fine. Checked contactor ( or relay??) - it does show 24V.
After replacing fuse AC does run for several hours.
What is causing AC to draw more current ? Motor ? Capacitor next to contactor ( or relay ??) or Contactor it self ?
Any help/suggestion is appreciated.
Thanks,
Mostlikely compressor. Contact pro, and don't randomly feed it fuses.
JHow would we know? We're not there!
time to call a service company, there's some serious problem that needs a pro to diagnose. Fuses are to protect the equipment. Replacing fuses like that destroys the equipment. Using a larger rated fuse destroys the equipment sooner.
It may NOT be drawing too much current.....
Before you call a AC tech......
When the fuse(s) "blow", are both their end caps still shiny copper/brass colored or is one cap darkened?
If it's the later, you may just need to clean the fuse clips and squeeze them down a bit so they make better contact with the replacement fuse. You should also look at the disconnect's switch blades to see if they look darkened by heat.
I say this because I've been plagued over the years by a more than one fused disconnects which after they'd been in service about ten years began to "blow" fuses because current flowing through the less than perfect contact resistance in the clips and/or switch blades raised local temperatures enough enough to heat the fuse end caps and melt the solder connecting that cap to the fuse link inside.
The heat darkened the end caps as though they'd been in a fire and the fibre bodies of the fuses were also charred and brittle next to the end cap. The fuses didn't really "blow", they just developed open connections inside when the solder melted.
HTH
Jeff
Monitor high side pressure and amps if you have the equipment. If the amps go up and high side is within specs for that unit then you have an electrical issue with the compressor/run cap.
Also check line voltage at disconnect.
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