[Shop-talk] AC compressor is tripping 20A breaker

[shop-talk2 at mcfetridge.org]

Hi All,

 

One of our A/C compressors is tripping its breaker periodically and I'm not
sure how to fix it.  I know when it trips because the upstairs vents start
to blow warm air.  The identical downstairs setup has not failed like this.


 

A yellow 20A wire runs from the panel to the outside compressor, once each,
for both of our identical units.  The 20A panel breaker is tripping in an
odd way also:  it trips (circuit open), but it looks closed.  If I nudge it
to the right (open) it gives while the other 20A breaker above it does not
give.  If I flip it to the right and back again, the power is restored.

 

We're renting the house, but plan to buy it as soon as an oil tank in the
ground is removed and certified clean by the state.  The current owners of 6
years say this has never happened before - the units are 6 years old.  So I
don't know if it has always been a chronic problem when the A/C runs a lot
in summer or if it's a developing problem.

 

My knowledge of household wiring is fairly basic.  Could there be a problem
with the wiring that is causing it to short?  It does not coincide with rain
at least.  If there is more resistance in the circuit, would that cause the
circuit to trip, or just make things hotter?  The owner wants to put in a
higher amperage breaker, which I don't consider a safe solution.  

 

Any thoughts?  Suggested steps to investigate the issue?

 

Thanks in advance,
Ian