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View Full Version : Old AC condenser fan motor - which wires are which?


HStevens
Jul 16, 2008, 10:34 AM
I have a Climatrol unit with an Emerson condenser motor that is shot. I bought an Emerson Rescue motor to replace it from the local AC supply store.

The wiring diagram was stored in the AC unit, and it is no longer readable. The three disconnected motor wires from the old unit are yellow, brown, and black. My question is: which wires on the new motor will connect to these yellow, brown, and black wires?

Worst case question: Do I need to buy an electrical meter to determine which wire is which? And if so, what is the method for distinguishing the wires?

hvac1000
Jul 16, 2008, 11:04 AM
There is a wiring diagram on the side of all motors. Follow it and you will be OK.

If you already installed the motor without making a copy of the wiring diagram use the motor model and use Google to find the wiring diagram.

I have an idea where the wires go BUT I am also afraid if I post it and you use it there could be a problem.
I hope you bought a new capacitor for the new motor. If not get one of the correct size.

HStevens
Jul 16, 2008, 12:17 PM
Yes, I have that wiring diagram. I am looking for additional information.

Let me re-state the question, because I found some additional information.

I disconnected 3 wires to remove the motor - yellow, brown, black.

(new info: yellow and brown go to the old capacitor, so that's easy - install the new capacitor and new wires and scrap the yellow and brown wires)

The wiring diagram shows a 3 wire hookup and a 4 wire hookup. How do I know which of those to use?

hvac1000
Jul 16, 2008, 01:27 PM
Actually you can use eighter one.The two brown wires go to the capacitor and the other two goes to the 240 volt side one wire on one leg and the other wire to the other leg. Naturally they attach at the contactor so the motor will turn on and off with the compressor.This is the simple explanation. The 3 wire hook up just uses a pass through connection on the top of the capacitor. More confusing than the four wire hook up.

Usually I never use the old wiring if the new motor has long enough leeds to get back to the contactor.

sammymh
Aug 28, 2012, 07:05 PM
My condenser fan motor will run for a couple of minutes a stop running and will keep this up until the circuit breaker in the house trips.

I went and purchased a new condenser fan motor, a dual run capacitor, and a single run capacitor for the fan.

The new condenser fan motor has 5 wires instead of 4. I hooked it up everything in the following way.

From condenser fan motor
Black to L1 on the contractor L1
White to L2 on the contractor L2
Brown to the new single run capacitor (right side, 1 of the 4 post)
Brown/White to the new single run capacitor (Left side, 1 of the 4 post)
Green to Ground

New Dual Capacitor
C post to L2 on the contractor
HERM to Condenser
Fan - NOTHING

My problem is that it is still doing the same thing.

Do I need to run any other wires, or is there another problem all together?

hvac1000
Aug 29, 2012, 05:29 AM
Please start a new topic since not may people will see this posted here as a add on to someone else's question.