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martinco
May 3, 2008, 05:39 PM
I have a problem with my RHEEM air package unit Air and heating, the blower motor won't start and it keeps blowing my 24v transformer, transformer literally blows up by doing an explotion noise. Now I am thinking that it might be the blower motor it self the one returnig High Voltage power to my transformer via the low voltage wires located in the motor. I already removed the low voltage wires from the motor but then I am afraid this would not work. Do you thing it might be OK to buy a new Motor?

KISS
May 3, 2008, 05:45 PM
The stongest possibility is a short in the 24 V wires heading to the relay. Disconnect bothe ends and do a continuity check between them and ground. There should not be any.

There are other possibilities, but put a 3A fuse on the secondary of the 24 V transformer or buy an energy limited transfomer.

Bet you can get the AC to start my manually moving the relay contacts. Do this forcibly and with something totally insulated. No 24 VAC required.

T-Top
May 3, 2008, 05:53 PM
Your blower motor should not have low voltage wires going to it unless it's a DC drive variable speed motor. If it is a variable speed motor you will have two pin connectors going to it(they hook up on the bottom of the motor.) one with three large wires and one with 7 or 8 smaller wires. I agree though it sounds like you may have high voltage coming in on the low voltage side.

martinco
May 4, 2008, 11:15 AM
The stongest possibility is a short in the 24 V wires heading to the relay. Disconnect bothe ends and do a continuity check between them and ground. There should not be any.

There are other possibilities, but put a 3A fuse on the secondary of the 24 V transformer or buy an energy limited transfomer.

Bet you can get the AC to start my manually moving the relay contacts. Do this forcibly and with something totally insulated. No 24 VAC required.

From: martinco; Thanks a lot man! You are a genius.

martinco
May 4, 2008, 11:34 AM
I diconnected the low voltage wiring leaving the transformer to the relay and there is no continuity with ground nor any continuity with the relay, now I talking about the relay that controls the speeds for the blower motor, do you think I might be a good idea to replace the main contactor relay? I checked the $$ and is only $24.00 to avoid the possibility that the relay coils are bad and passing high voltage into the low voltage.
Please advice, thank you.

KISS
May 4, 2008, 02:32 PM
You missed what I said:

Disconnect the wires to the relay.
Disconnect the transformer.

Now measure across the wires that went to the relay.
Measure from each disconnected wire to ground.


What happened when you puched on the relay contacts? You can only do this if they are exposed.