Fridge Compressor Motor Runs Slow

I'm afraid your fridge turned into a toaster, and toasted itself. Sounds like a shorted winding.

Hi thanks for reply. When you say shorted, to where? Have checked for shorts to ground and all good. Do you mean like an internal short within the winding? If so could this have been caused by the motor getting hot because the start cap stayed engaged or some connection with the 130uF it was given?

Thanks.

Yes, that's the idea, although it isn't very certain. The idea is that if some windings get hot, the insulation on them can melt, thereby shorting together one or more loops. At least that is consistent with your reduced resistance reading.

Right on the money. More than likely you had a dirty condenser that caused the compressor to overheat, shellac its bearings, and open a portion of your start winding. At least it has not grounded causing a burn out and a acid clean up step to the system repairs. As far as the running slow to not build the EMF to drop out your amperage relay that is from a combination of tight bearings and lack of start winding to get it up to speed.

Replace the compressor - do not attempt any more electrical components to try and "rig it to run" or you will burn it out and the repair just gets more expensive.

I concur.

(Which I say partly because I do, and partly because it reminds me of "Catch Me if You Can". Some of the real-life events portrayed in that movie occurred a couple miles from here.)

If your run capacitor is showing 10 ohm steady resistance, it's shot....

I'm gonna guess he meant 10 μf.

Sorry "typo". Yes I did mean 10uF. I'll blame it on a late night!!

How true..... compliment.

The only other possibility is that a low value resistance is included in the package, though I personally have never heard of such a capacitor. myself.

Bleed resistors are usually of a high resistance value and are usually externally fitted.

I'm with you on this one in spite of the OP's data sheet.....

Possible causes may be

· Defective overload protector

· Defective run capacitor

· Suction pressure too low or high

· Shorted motor winding

· Erratic thermostat

Hello,

1. What is your refridgerator setting (mean at what set point)

2. Try to switch OFF all the fridge for few minutes.So, that thermostate will get cool properly. Some time, once thermostate got tripped it will trips again.

3. Try to check capacitor. If it is not showing consist reading then replace it.

4. Try to do reinsulation on winding. Sometimes, due to some manufacturing defect, continuous use, improper ventilation etc. winding may get weak.

This may solve your problems.

All the best.

Greetings.

In cases like this when the capacitor is shot I have used a Supco Quick Start which is fairly inexpensive at Appliance Part Stores like Reliable Parts.

The quick start comes in several flavors depending on the compressor type and compressor size.

It is worth the time and I have resuscitated many "dead" compressors with one.

Have a Great Day,

Oly

The motor is now defunct to my mind.

The reason is maybe that the start cap stayed in circuit because of the start relay failing.....then a motor overheating is almost always the result.....shorted windings etc..

You need a new motor, new start relay and new start capacitor......check the run capacitor is good (assuming that there is one), "just in case!"

Most of the motors I've run across (refrigerators, central A/C units, furnace blower) seem to work fine with run caps with capacitance in the same order of magnitude. (Make sure the voltage rating is equal or higher however.) I've substituted caps of 1/2 the capacitance and they work fine and similarly with twice the capacitance with the same result. However, I do generally go back and replace them with the correct value when I can get them, but in a pinch . . . .

I'm with Tornado and Andy, you probably have an internally shorted winding at this point.

Good luck with your quest.

Thanks all for your contributions. It would appear that the general opinion is pretty much as I suspected, but hoped wrongly, that the motor is finished. Interesting is that the start relay seems to check out as functioning ok which would point to the root cause possibly being the "engineer" with his bad capacitor. I had originally thought that perhaps the relay was at fault but find it hard to believe that it could be bad and then be ok.

Many thanks all.

Relays can get their contacts welded together. A short sharp movement (dismounting and testing for example) will sometimes free it up. It will eventually weld together again, so don't penny pinch, replace it too......

It is possible to run two wires, one from each contact and wire an external (small low wattage and voltage) bulb and resistance across the contacts. The bulb will light as long as the contacts are open, which they will usually be.

Or run a single wire from the "non live side" contact and add a resistor and small bulb to neutral if available.....that will light when the contacts close....I don't have a schematic for your motor for exact details, but this should give you the idea......that way you can keep an eye on the relay.....now you can retain the old one!!!!

You state the compressor is just over one year old. The service engineer has condemned the compressor. What is the length of warranty in your warranty policy? Some are protected one year on a replacement and some are covered five years on a new refrigerator by the appliance mfg. And some compressors now come with over five years. Some compressor mfgs require a return to factory for a teardown with results sent back to the service engineer. Is the whole system just over one year old or was this a field R-12 replacement? So many if ands or buts and smoke and mirrors but it's clear many of us think you have achieved the maximum smoke rating on your start winding

Bingo! The Bearings are the final cause of death. JG is right on all counts, if the windings are shorted or relay is bad the unit will trip on overload. With bad bearings the compressor will slowly try to start & drag the voltage down until it gets to the point that the current relay will not open the start winding / start capacitor circuit.

PSU VTI Rocks!

Sasnak,Amen to the bearing failures reply

Before that big upset in the industry in 95 we would find a lubricant to fit the application
Now it seems we have to change the application to fit the lubricant
or we have bearing failures and related winding burn failures as suspected in this forum What's next after POE? I hope we're not out of options to keep non-toxic non-flammable refrigeration within financial reach of common man.

OK Sasnak, Glad to hear a local fellow member chime in from the flatlands of Kansas.