I have an old Weather King (RUC 936-1L) condenser unit, the fan stopped working and the compressor started wining.

I replaced the fan, run capacitor and start capacitor, it started to work but then the fan started to randomly shuts off, it starts but only runs for about 8 minutes, turn off for about 3 minutes, then it will run for about 5 minutes, off again for about 2 minutes, then it will run for about 3 minutes and then it wont turn on again, the compressor starts to make that wining noise.

I then replaced the relay and the contractor...still the same issue as above... can some one give me some steps to troubleshoot...

Original fan: 1.2 amp; 1/6 HP; PH:1; 208/230V
Replaced with: 1.0 -1.1 amp, 1/6 HP;PH:1;208/230V (less amp on the new one)



Old Motor Start Capacitor: Mallory 189 MFD 330 VAC
New Motor Start Capacitor: 189-227 MFD 330 VAC (had to use the old diode from the old capacitor)

Old Contractor: 30A 1 Pole Contactor with 24V Coil
New Contractor: Rheem Ruud 30A 1 Pole Contactor with 24V Coil

Old Run Capacitor:40 uf +5uf 370 vac 60 hz
New Run Capacitor:Carrier P291-4054 - 40 + 5 uF MFD x 440 VAC

Matched the relay and replaced with a MARS 69 Potential
Relay.

Can someone shed some light on this?

 

It sounds like the condensor fan is cycling on high heat.
When the fan stops running.... see if the motor is extremely hot.

The new fan motor may require a different sized capacitor from the old motor. Check that too.

 

Thanks Pete, will check after work today & post.

I got the new fan from "grainger" item # 1UME8, as per grainger this motor's required capacitor is : 5 microfarads 370VAC.

original was dual run capacitor - 40 + 5 uF MFD x 370VAC, new one has same microfarad rating except it's 440 VAC.

What do u suggest I jack it up to?

Again thank u so much for your time.

 

That cap appears to be the correct value.

Is it spinning in the right direction ? The air should be blowing upwards.

 

When the fan stops running the motor is extremely hot.

It is spinning correctly and the air blows upward.

I took the top cover off and double checked the fan spin direction by pressing on the test button on top of the contractor, it immediately spins.

So as you said fan may be stopping because of the motor getting hot.....

 

Ideally if I was servicing it I would use a clamp on ammeter (amprobe) to see what the current draw was.

Originally I thought the speed was too slow but it appears your condensor does use an 825 RPM motor.

I left a link for the wiring but I don't think you have wired incorrectly.
grainger/ec/pdf/HVAC-Condenser-Fan-Motor-Wiring-Diagram.pdf

 

Pete: thanks very much... wired wrong, corrected now it running fine...thank you.

Original fan had three wires with the brown wire to the run capacitor. Grainger's: 1UME8 had four wires, two wires marked to fan capacitor, a brown and brown white so I connected both the brown and brown white to the new run capacitor...that is when the fan was getting hot and cycling on and off.

I looked at the original wiring schematics and the one you sent, and took off the brown white wire off the run capacitor and now it no longer cycles on and off and runs very effortlessly.

I also used a clamp on ammeter and now the brown fan wire connected to the run capacitor draws 0.03 A, the black compressor wires is drawing 14.1 A......as per specs the fan motor is to draw 1.0 -1.1 amp....but the clampmeter registers 0.03 amp. Should I experiment with removing the brown wire and connect the brown white to see how much amp it draws?