Roof A/C kills the generator when the compressor kicks in

[DEL]

Sent: 7/16/2002 9:05 PM

My 77 Minnie Winnie does not have dash air.
It has a generater that is an Onan 3kw.  When trying to run the a/c off the gen. it will kill the gen after the a/c ompresser kicks in. 
The a/c will run while plugged into shore power, but makes a loud roaring noise.  Puts out some cold air however.  Seems to be drawing a lot of current. 
Ran it today with the cover off (top) and the compressor is very cold with a lot of condensation.  I would figure that the compressor unit would be hot? 
It is the original a/c so suppose that it will have to be replaced?
Someone at some time has added freon as the low side is fitted with one of those clamp on valves. 

Thanks for any advice that you might have.

del

[HAL]

Sent: 7/17/2002 8:27 PM

HAL HERE. YOU WILL NEED A GET AN  AMP METER. YOU NEED TO FIND OUT HOW ANY AMPS THE UNIT IS DRAWING. ON STAT UP THE A/C WILL DRAW UP TO 30 AMPS. ONCE IT STARTS IT SHOULD DROP TO AROUND 12 TO 15 AMPS. AS TO THE SOUND IT COULD BE SEVERAL ITEMS. ARE THE AIR FILTERS INSIDE OF THE INTER COVER BLOCKED? CHECK TO SEE IF THE FAN BLADE IS SPINING ON THE MOTOR SHAFT. YOU CAN DISCONNECT THE FAN MOTOR FOR A SHORT TIME WHILE THE COMPRESSOR IS RUNNING TO SEE IF THIS IS WHERE THE SOUND IS COMMING FROM. YOU COULD HAVE A BAD FAN MOTOR. ARE THE FINS CLEAN ON BOTH THE COILS,AND ALLOW THE AIR TO FLOW THROUGH?  IF YOU HAVE ANY MORE QUESTIONS FEEL FREE TO CONTACT ME AND I WILL TRY AND HELP YOU.

[DEL]

Sent: 7/23/2002 11:17 PM

Thanks for your interest.

The filters (inside) are new.  Both of the coils are clear and clean.  The fan and fan motor are quiet.  The noise seems to be a vibration in the sealed refer unit (what ever its called) and is causing the ceiling of the rv to amplify the sound.  It puts out cold air, probably not as cold as it should be.  I will measure it.  I didn't have an a/c ammeter.  Went and bought one today..  If it is not too hot here tommorow I will check and see how much the start and run currents are. 

I know, this unit is 25 years old and don't expect to get it to run like a new one.  Howsomever, I would like to keep the old girl original as much as possible.  I can say " look here at this a/c.  It is 25 yeaars old and still working".  Has a metal housing over the unit (not plastic) and it has 3 speeds (grin)

Thanks,  del

[DEL]

Sent: 7/24/2002 10:20 PM

I checked the current draw on the a/c today.  It pulls 30 amps for a second, then settles down to 15 amps.  It seems to be functioning ok.  This was while on shore  power.  Went to generator power and the a/c killed the gen after a short while.
Cleaned the generators points and adjusted the carb.  It will now carry the a/c ok.

The darn thing still makes a lot of noise.  Especially inside the rv.  Guess I will have to live with that, or shell out for a newer and less noisey a/c.

Anyway, I now have a new tool that should come in handy in the future.  (An
Amprobe)

Thanks Hal for you help.  I wouldn't have known how to test it without your input.

del