If you have someone turn the thermostat up and down, you will hear the
contactor click in and drop out. It operates on 24 volts which it gets from
the blower unit. Near the condenser should be a disconnect. open the
disconnect and find the two terminals marked "line". If you touch the
terminals of a meter across these two terminals you should get 240 volts. If
not, check the breaker feeding the condenser



"Jack" wrote in message ...
Hello,
Before I call the pros, I am going to do some basic troubleshooting on my
central AC. The fan and compressor are not coming on. I can hear a
low-voltage hum. I will start with a meter to make sure 220v is getting
to the contactor and also 220v is coming out of the contactor.
.
Since I don't have any experience with 220v, I would prefer to not belt
myself. Out of the wall is a pink and black wire to the contactor. Where
do I put the meter leads to test it? Any danger moving the leads from
terminal to terminal as long as I don't hold the leads by the metal end
(just kidding). Also, when the unit comes on, should I see the contactor
move, or click, or what?? I didn't see anything like that, so I am
thinking 220v is not getting to the unit.
.
Thanks for your time.
-jack