Before I Scrap Faulty Whirlpool ARC7472 Fridge Freezer?

[smarty]

I had an electrical fault on Friday in the box where the meter is outside the house, it appeared to be making an arcing sound and the lights were dimming on and off in the house and then it caused the RCD to trip on the downstairs sockets. I got EON out and there was a bad connection in the box. Anyway the next day I noticed that the fridge freezer had failed which was full of food  I thought I might get something from the insurance company but I do not have accidental damage cover. So before I scrap the machine I just wondered is there anything that I could look for.

The fridge freezer is a frost free Whirlpool ARC7472 around 7 years old and has been faultless up until now. This is a basic unit with no digital displays or control panels. Basically the compressor is just not cutting in at all and both the fridge and the freezer are not cooling. The circulating fan in the freezer is running more or less all the time. Obviously if the compressor has gone or some other major part then it is not worth bothering with at all. I have read a little on the internet and have tried to locate the thermostat. I took the control panel out of the fridge part that has the 2 dials in for setting the fridge and freezer temperatures. One of the dials is connected to a potentiometer I cannot remember which one probably the freezer as it has a fast freeze setting on it; the other dial is connected to nothing electrical. At first I thought that this was a thermostat but after looking on the net at spare parts I believe it is a thermostat potentiometer as I expected the thermostat to have a phial after further reading. From what I have read the thermostat should be inside the fridge but I could not find it. I just wanted some idea where it might be and how to check it with a multi-meter please? I have repaired a washing machine that I used to own numerous times but I am finding this a bit more difficult.
I just wondered if anybody had any idea before I scrap it and buy some cheap model that might be more trouble. Thanks for any help.

 

[Mikefromlondon]

You need to check if the compressor is getting voltage to its terminals, as the problem you had with your electrics may be or may not be due to this compressor, in other words, if your compressor motor went i.e. short circuit, it may have imposed heavy loading on your circuits and the weakest point which being your termination at the meter box revealed itself and started to arc!

Or it is quite possible that the weak or poor connection inside the meter box cause your compressor motor to burn out, since, if the compressor motor does not get a good strong reliable voltage to kick start, then it may
not kick into motion and all that arcing and hissing on the elctrical supply caused the motor or its starter to burn up.

The compressor motors use a starting device usually a thermistor whose resistance goes high with temperature, so when the fridge is first plugged in, the thermister is at room temperature, and on switching on the current, the thrmister will inrush full current to the motor, and kick start it, and in a few seconds it will get quite hot that the amount of current now passing through it will reduce substantially, and now the compressor will not require all that inital starting current and will happily be running on lower current, so check your thermistor, it should have a very low resistance when cold, oh, once the motor is running, the thermistor will continue to maintain its heated state so that it does not become cold again and start passing more current, so whatever current it is passing after it has got warmed up, that current will maintain its temeprature and continue to run the motor, motors also use a a secondary windings which draw much less current to make them run but not sufficient to kick start them, hence the thermister is what kicks the starting windings (primary windings)

Before discarding, test your compressor motor, check on the web or youtube various circuit configurations for fridge motor circuits, they are not that difficult to sort, as long as you are reasonable confident in handling mains, and safety concious of dangers of mains! so play safe and take precaustion with electrics, only fiddle with things if you know what you are doing.

 

[smarty]

Thanks for taking the time to reply Mike it is very much appreciated. Luckily my brother had a spare old fridge freezer that I could borrow. I have managed to get hold of a wiring diagram for this machine, it's a shame that I cannot attach it to the post. I am quite good at basic fault finding with a multi-meter and I am aware of how dangerous electricity is. Its just knowing what these parts do and how to check them, such as the compressor start relay, and PTC. I will check for basic 240 volts at the compressor first though. Thanks again.