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Hi
Not much of a domestic fridge man I’m afraid as all my work is ammonia industrial and commercial, but here goes.I had a look at a domestic unit for someone(she’s alone and elderly so I felt obliged to do so). The fridge freezer is integrated and I have not the foggiest idea of the make, because there isn’t any info on it. The refrigerant (to my dismay) was R600a (isobutane)- I had hoped it would be R134a as I have a bottle of that in my van.
The light is on and the evaporator fans run, but the compressor doesn’t. The resistance over the windings is OK etc. You can here the click as the compressor would normally start, but nothing happens. Theres a electric box that plugs into the compressor, and all the circuits are live and have correct voltage etc, except the two wires L and N from the capacitor. They are showing continuity on my voltmeter with the compressor attached, when the compressor is disconnected then there is nothing at all not even continuity, although there was 230V across one of the plugs that attaches to the compressor with it disconnected, but nothing over the other terminals.
I have no R600a gauges so will need to buy them, and have no idea of the weight to charge etc. But I think the capacitor is bad. I cannot test it with a meter as it is sealed, but I need a new one if anyone can help. It is a ICAR ECOFILL MLR25PRL4/5403051(possibly the latter is the serial) rated at 4 microfarads(is this a run capacitor-I assume so because of the rating). If this doesn’t work then the compressor must be shot.
Any advice is more than welcome.
JamesPS I also posted this message on the trade spres section for help in finding the parts, but need the technical advice as well.
Re: Faulty fridge freezer
James,
Take out the salad crispers in the bottom of the fridge and there is bound to be label stuck to the inside of the fridge with the model details on and the R600 charge will be there too.
If the compressor isnt running its not going to be a system fault anyway so dont worry about it. To check the capacitor you need to disconnecct the leads from the cap so they are not connected to anything else, connect your megger to each lead and press the button, you should get a low ohms reading at first that should fall back to a high ohms reading as the cap charges. On releasing the button your megger should read a voltage as the cap discharges (dont touch the leads till it has discharged!). If this happens and assuming it does not read to earth,then the cap is ok. The most likely fault reading will be either open circuit or short circuit but cap failures are rare.
Its not often you get a totally dead compressor, they usually make some attempt at a noise at first. You will have some sort of relay too but I think we need more info to diagnose this.
2 things to look out for, if it is a frost free fridge freezer, the comp is often not switched on straight away althought the fan is running, it may come on some 20 mins later in some cases and although anyone here can supply a 4 uf cap, it really should be an encapsulated type to keep within the hydrocarbons design spec.Re: Faulty fridge freezer
I don’t use a megger for cap testing. I have always used an analogue multimeter. Connect the leads,then reverse them. The ohms usually will swing round to zero and then rise up towards infinity. I hadn’t got it with me as this was not a business customer. The relay I assume is integrated in the plug in box for the compressor, and there was no label under the salad boxes or anywhere else, so no charge info I’m afraid.
The compressor clicks after a short while of the unit being switched on, but nothing happens. Why though would there be no voltage from the capacitor leads ? Why can’t these things be like commercial units !!!!James
The label- she had removed it and still has it in her kitchen. It’s an Ocean APM 6825, and the charge weight if I have heard her correctly 42g-I know that these hydrocarbon units need less gas but is that correct ? and what sort of pressure would that create ? I shall ask for a capacitor in any event from the trade spares forum.
Re: Faulty fridge freezer
Yes, that weight would sound about right. and is measured exactly to the gram hence the need for more accurate scales than that we use for older refrigerents.
Although your meter will check if the cap is ok, sometimes they can break down under high voltage such as it would be subjected to in normal use and a megger will probably show this rather than the 6 odd volts whatever form a ohmeter. Try the cap as its the cheapest option but the click may indicate a siezed compressor.Re: Faulty fridge freezer
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quote=”jack-frost”]Hi
You can here the click as the compressor would normally start, but nothing happens. Theres a electric box that plugs into the compressor, and all the circuits are live and have correct voltage etc, except the two wires L and N from the capacitor. They are showing continuity on my voltmeter with the compressor attached, when the compressor is disconnected then there is nothing at all not even continuityforgive me if i’m mis-understanding but if you can hear a click then one of two things must be happening. one is either this appliance has a relay starter which is quite common to burn out, or two, after a period of trying to start, the compressor overheat built into the windings is cutting out. the capacitor is just there to make the appliance more cost efficient when running but would have no real assistance in making the compressor start (a capacitor measured directly will not show continuity unless defective). the question first is, is the box that plugs onto the compressor (the starter) a relay type or ptc (thermistor) type. if its a relay starter i’d change that first. if not then most likely your compressor seized.
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