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esquire1 · May 19, 2007, 03:04 PM

Rheem package unit and the condensing fan motor runs non stop. Thermostat is off and the contactor is open but the fan motor will only shut off if I shut off the breaker. Any help please. Thanks

hvac1000 · May 19, 2007, 03:44 PM

The motor is wired on the wrong side of the contactor. If the compressor is off this can be the only thing I can think of because the contactor is supposed to control the condensing fan motor and compressor at the same time.

esquire1 · May 19, 2007, 04:02 PM

The incoming voltage is at the bottom of the contactor and has 240V and the fan motor wire is on the top(the supply side and contacts are open)with 0V and the fan is running. It has me puzzled. The compressor is off. Push the contactor in and the compressor comes on

hvac1000 · May 19, 2007, 04:31 PM

I have been around this industry for more than 40 years and what you are saying is about impossible. Sometimes the contactor will not open but it looks open. This is when the contacts have welded together. You might disconnect all wiring on the line and load side and check with a meter.

Power has to get to the motor for it to run and something is feeding the motor power. Also look for a bypass circuit of some kind and if that fails cut or pull one of the power wires going to the motor and see if that stops it.

hvacservicetech_07 · May 19, 2007, 04:53 PM

There has to be voltage on the other side of that contactor somehow, you have tested the motor lead and there is 0 volts? Is it a single or double pole contactor? If it's single pole then you'll have 120 volts through the contactor all of the time so be careful.

esquire1 · May 19, 2007, 05:21 PM

It is a sigle pole. The contact are not welded are are in good shape. I can push in on them & the compressor will start and when I let off they snap back. I'm puzzeled. Could it be a relay as the black wire from motor ties into one going to relay that is in clear box with 3 sets of contacts but I can see them and none are welded. When I remove the orange wire of motor from the load side the motor does stop.

hvacservicetech_07 · May 19, 2007, 05:31 PM

How old is the unit?

esquire1 · May 19, 2007, 05:41 PM

I'm guessing 10-12 years

hvacservicetech_07 · May 19, 2007, 07:41 PM

Ok, with the power on and the contactor open, use a voltage meter and test each side of the contactor to ground, there has to be voltage there.

letmetellu · May 19, 2007, 07:51 PM

Since you have a contactor that only breaks one side of the lines you always have 120 volts going through the other side of the contactor. So here is a possibility, the motor has some how shorted to ground and the 120 volts is supplying the motor and making it turn, if this is the case the motor will only turn at about half the speed that it is suppose to because of the low voltage. This is something rare but it can happen. Since you seem to know something about electricity here is a test you can make, turn off the power, disconnect the wire from the contactor that is one on the break side of the contactor. Leave it disconnected, you might put a wire nut on it just to be safe, then turn the power back on, if the motor turns then you need a new motor and capacitor. If this was the problem please let me know.

hvac1000 · May 19, 2007, 10:57 PM

If you have a single pole contactor the reason for this is to keep 110 volts at all times on the compressor windings. This acts like crank case heater and keeps the oil warm in the compressor. I guess it could be a feed back of some sort or the motor is wired wrong.

esquire1 · May 20, 2007, 05:16 AM

Originally Posted by letmetellu

Since you have a contactor that only breaks one side of the lines you always have 120 volts going through the other side of the contactor. So here is a possibility, the motor has some how shorted to ground and the 120 volts is supplying the motor and making it turn, if this is the case the motor will only turn at about half the speed that it is suppose to because of the low voltage. This is something rare but it can happen. Since you seem to know something about electricity here is a test you can make, turn off the power, disconnect the wire from the contactor that is one on the break side of the contactor. Leave it disconnected, you might put a wire nut on it just to be safe, then turn the power back on, if the motor turns then you need a new motor and capacitor. If this was the problem please let me know.

I have disconnected the lead of motor from contactor and the motor stops. I also moved it to the other side of the load side of contactor and it will run. Whow?? I do know some about this field but it has me puzzled

hvac1000 · May 20, 2007, 07:28 AM

Feed back through the compressor/crank case heater. Disconnect all 3 wires on the compressor and insulate/protect them from ground. Then start up unit and see if fan runs. If it does you have one leg of the compressor or crank case heater going to ground.

esquire1 · May 21, 2007, 06:48 PM

Originally Posted by letmetellu

Since you have a contactor that only breaks one side of the lines you always have 120 volts going through the other side of the contactor. So here is a possibility, the motor has some how shorted to ground and the 120 volts is supplying the motor and making it turn, if this is the case the motor will only turn at about half the speed that it is suppose to because of the low voltage. This is something rare but it can happen. Since you seem to know something about electricity here is a test you can make, turn off the power, disconnect the wire from the contactor that is one on the break side of the contactor. Leave it disconnected, you might put a wire nut on it just to be safe, then turn the power back on, if the motor turns then you need a new motor and capacitor. If this was the problem please let me know.

With the lead disconnected, the motor stops. The black wire from motor is connected to a relay in a clear box. Could that be where the power is coming from?

letmetellu · May 21, 2007, 07:33 PM

I have decided that you must have a heat pump although I don't think you have ever said. If it is a heat pump the clear box that you are talking about is probably a relay and it could be where the problem is that is making your fan run all the time.
If I were you I would spend the money to get a tech out to check out the unit, if you start replacing circuit boards and reversing valves and other things trying to trouble shoot your trouble you could spend quite a bit of money and still not have the right thing fixed.

I have one other suggestion, take all the wires off the load side of the contactor except the black wire going to the fan motor, but be sure and mark where all the wires came off the contactor so you will know how they go back. This way you will only have one wire connected to the motor, it will be the one that is no broken by the contactor. Now turn the power on and make sure the thermostat is calling for cooling. Now if the motor runs it has to be the motor. One of the field windings have gone to ground making it a 120 volt motor.

hvac1000 · May 21, 2007, 08:53 PM

Something tells me this person does not have a real problem. This person has been posting on other boards pulling the same stuff on them. This person just wants the attention for a problem that is non existent

esquire1 · May 22, 2007, 04:03 AM

Originally Posted by hvac1000

Something tells me this person does not have a real problem. This person has been posting on other boards pulling the same stuff on them. This person just wants the attention for a problem that is non existant

This is a real problem. I have posted on other boards and I'm trying to find out the problem. I have gotten some good advise. I am learning the industry and have never ran across this before. If you can help me out , I would appreciate it. I guess for now I will move the other wire to the load side of contactor to solve problem temp. the check the relay