Andrew Taylor wrote:
The heat has motivated me to have central air installed at my home. I am
trying to avoid getting ripped off on the electrical part of the job.

My understanding is that central air conditioning units generally pull
about 30 amps, depending on the size. At any rate, when I look at my
electrical service box, there are two 20 amp breakers that are unused.
Is it easy to somehow combine these two to support the needs of the
central air? Should the contractor that installs the AC be able to
handle this as a standard part of the job, or am I looking at additional
expenses?

Thanks.


If the breakers are truly unused, they'll pull them out and install the
double 30 or 40 that your new compressor will need. What are you gonna
do for the air handler? Unless you have central heat already with an
air handler, tou'll need at least one more breaker. If your electrical
service is large enough but you are just out of spaces, use the 2
remaining slots for a 60A or 70A breaker to go to a subpanel. If you
have a 100A panel you may can ad a feed-thru lug kit to it and wire a
small 100A "main lug" subpanel right next to it without using those last
two spaces. (if you use feedthru lugs, the subpanel and the feeder
wires must be rated for as much amperage as the main panel)

Bob