DIYbanter - View Single Post - Air conditioner humming outside but I have shut off the breaker

George E. Cawthon

Joseph Meehan wrote:
wrote:
Hi,

I went out into the yard this evening and heard my air conditioner
humming. The unit hasnt worked properly since we had a major power
outage and so the only way to turn it on or off is at the breaker. I
removed the wires going into the breaker but the unit is still
humming. I openned the unit and the only power wires I can see are the
black/white/ground. It is a very old sears model and I cant find any
other shut off switch. What's going on!! Should I be concerned about
the humming and if so, how can I completely remove the power to the
unit without getting an electrician involved. I even tried going
breaker by breaker to see if there was a wire touching but nothing
stopped the humming

Thanks

You apparently did not shut off the right breaker. Remember that your
furnace is not likely on the same breaker as the A/C unit. The A/C unit
should have a 220V breaker and there should be a shutoff in the immediate
area of the unit.

Why not put the AC and the furnace on the same
breaker? Course my furnace was electric so the
power supply was 220 at 100 Amp. I just extended
the line to where I wanted the AC unit and put the
box and AC breaker there. No reason to use
separate lines since the AC and the furnace can't
run at the same time.

Course if you have a gas furnace and a 120V line
that's another story.