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-   -   AC amp problem (http://www.houserepairtalk.com/f8/ac-amp-problem-554/)

cam 03-23-2006 10:38 PM

AC amp problem
 
Have to change the 30amp circuit on the outside AC unit to a 20 amp. Anyone have some suggestions on how to do it?

inspectorD 03-24-2006 06:07 AM

Why?
 
Everyone already know's I'm going to ask "why"first.
Your A/c unit needes the 30 amp for start up.
If you are keeping the a/c unit you will not be able to start it with a 20 amp without tripping the breaker.

Get an electrician and do it safe,
InspectorD

CraigFL 03-24-2006 06:22 AM

Sometimes people believe that putting a 20A load on a 30A circuit can cause too much current flow and blow the device. This is not true normally because the 30A circuit breaker is that rating to protect the wires from exceeding that current. The AC unit will take only the current it needs.

That said... As the AC unit gets older, it can draw more and more current. Sometimes "hard start" capacitors are put into the circuit to help the compressor start. So, if you're trying to protect the compressor from exceeding its nameplate current, you could put a 20A breaker in place of the 30A but as "D" says, it may trip more often due to the startup current. In the end, when it's time for your compressor to go it will exceed even the 30A breaker rating and blow it.


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