Failed fridge - symtoms

[dal5band]

Our fridge has stopped cooling the sysmtoms are :

Light on when door open
Thermostat led comes on
Motor hums and rattles for 10-15 seconds then stops, repeats every few minutes.
Compressor gets hot, too hot to touch if I leave it on for 15 mins (from cold)
But no cooling

Is it worth calling out arepair man or just go for a new fridge ?
Dal

 

[Leccy758]

Sounds like possibly the start relay or run winding have failed on the compressor.

Compressor failures are rarely worth repairing on domestic fridge/freezers.

 

[dal5band]

thanks confirms my thoughts
- I have confirmed thermostat is sending a live back to the motor as I guessed anyway so the problem is definately down below !!

If the motor is humming , surely the relay is switching ON ?

We'll go for a new fridge tomorrow.

Thanks

 

[Leccy758]

The relay switches on start winding then after a short period it changes to the run winding on the motor

 

[dal5band]

OK done some tests -

The starter device is a Danfoss 103N0021. It says 25 Ohms on it and I measured approx 25 ohms accross what looks like flat coil inside. So the coil may still be OK ??
There is a 4 UF capacitorconnected accross the coil bolted to the fridge frame - can't test that.

Tested continuity between the windings - seem ok (about 25 ohms between pairs of pins (3 pins on motor). Nothing shorting to earth.

That's about my limit - the Danfoss thing is about £8 on ebay.

 

[Leccy758]

testing across the windings as you had you should have two pairs that are low and added together they should equal the resisitance between the last two terminals
example
A-B 25 ohms
A-C 25 ohms
B-C 50 ohms
Some multimeters have a test facility for capacitance, if you dont have the facitlity or know someone who does (we test them for customers who bring them in) you cant check them for going low in value.

Another reason the compressor could be stopping after a short while is due to the overload/temp cut out on the compressor (usually near the relay) operating due to the compressor overheating.

 

[dal5band]

We are using the backup fridge so haven't got around to chaning the Danfoss start device on the failed fridge - I will update in a few weeks time.

 

[dal5band]

update: changed the starting device - no change. Compressor seized, got new fridge.

(windings were ok, motor hummed when turned on but would not run. when the motor got hot the thermal cut out operated and it switched off. cycle repeated every few minutes on cooling.)