Gas and Oil Home Heating Furnaces - a/c unit flipping breaker

I have an older model Rheem a/c outside unit that about two weeks ago had to have the motor replaced. Since that time, the breaker flips atleast once a day. When I flip the breaker back on, it works fine and cools fine, that is until it flips off again. I have had the a/c repairman take a basic look at it when he was here a week ago working on my other unit and he said he couldn't spot anything after a general look.

We have also had to have the freon charged in the unit about six weeks ago. I don't know that that has anything to do with this current problem, but I just thought I would let you in on the whole picture.

Any thoughts or advice would be greatly appreciated.

E. Seibert

This can be a tricky and tedious hassle to find. The easiest way is to have an amp reading taken with a clamp style ammeter at the breaker panel while the unit is running. (This assumes that nothing obvious like skinned wires or loose connections are found.)

You just watch the amp reading until the breaker trips. If the breaker trips and the amp reading is within the the limits stamped on the ac unit's label, then the most likely problem is an aging or weak breaker, an easy replacement item.

If there is a high amp draw, then there could be a problem with anything from failing compressor or fan capacitors, bad contactors (a worn contactor can produce intermittant high current draw, especially when the system is cycling on and off a lot). The final and worst case is the compressor itself.

Since this problem started with the new motor (I assume condensing fan), the wiring job on that is a good place to look. Often inexperienced installers will attempt to wire replacement motors identically to the OEM motor, and accidentally create unexpected problems.

You're A\C Tech may have over charged your unit also resulting in a strained compressor.