RV Repair: Rv overhead airconditioner, fan motor, heating bills

Question
Hi Larry,

  i have a question about our overhead airconditioner. It is  Coleman TSR Mach3. The rear one works fine but the front one has an issue. After you start it, it will run fine for 15-20 mins. After 20 mins it will start running loudly and stop blowimg air. If you leave it it will eventually pop a breaker. If you turn it off after the 20 mins and leave it for half and hour or so you can run it for anouther 20 mins with no problems. Any ideas?  

   Thank you Cheryl

Answer
Hi Cheryl:

Here is what is happening. The fan motor, that cools the condenser up on the roof, and also blows the air across the evaporator coil, is getting hot and shutting off on thermal overload. The motor probably has worn bearings in it. When the fan shuts off on overload, the compressor continues running until it too overheats, due to lack cooling across the condenser. When this occurs the amperage of the compressor increases significantly, thereby causing the circuit breaker to trip out.

Based on all you have told me Cheryl, You should have someone check out the fan motor, and replace it if necessary. Here is something also to consider, depending on the age of the unit, the parts and labor to repair may be close to half of what a new unit would cost. You may be better off just to get a new unit, or better yet consider a heat pump, that can help cut down on the cost of heating bills.

Hope this helps you, please let me know how you make out.

Regards, Larry