So it's time to dump your old broken refrigerator in a landfill? Even if it can no longer be repaired (for example, due to freon leakage), it still has valuable working units and spare parts that must be removed! This primarily concerns the refrigerator compressor. It will come in handy more than once for pumping air, for example, in wheels or for making a homemade painting machine - an airbrush. To remove the compressor from the refrigerator, you will have to unscrew only 4 nuts and cut off only 2 tubes with a hacksaw - input and output. The third tube (freon) is jammed tightly. In the immediate vicinity of the unit, a copper tube can simply be eaten with nippers rather than sawed off. Of course, before proceeding with the dismantling, the refrigerator must be disconnected from the outlet!
The next stage is checking the removed unit for operability. To do this, it must be connected to the electrical network. If the compressor is running, a hissing sound is clearly audible - it sucks air into one tube and throws it out into another. Remove the unit from the old refrigerator as carefully as possible so that the oil in it remains intact. You need to cut the cable going to the temperature sensor, then you need to measure the resistance and study the location of the closed contacts that will be used during further assembly, very well if the electrical circuit of the old refrigerator is preserved.
Preparatory work
Having identified the outlet pipe from the compressor, it is best to mark it immediately, because an oil filter will need to be attached to it. In order for the used compressor in the new device not to overheat and not to fail prematurely, it is better to install a new relay to it, ideally if the relay is original, corresponding to the brand of the old refrigerator. To properly connect the relay, you need to study the refrigerator circuit and make the connection in exactly the same order that was in the refrigerator and which shows the circuit. If no documents are stored on the refrigerator, a circuit diagram can be found on the Internet.
Also, the new device will have to be equipped with a receiver, which you can buy in a store or make yourself. For assembly, you will need a plastic bottle, through which the inlet and outlet tubes will pass through the holes in the lid. After inserting the tubes, the bottle should be poured with epoxy resin, and the bottle should be with the lid down until the resin hardens.After the resin hardens, the tubes and cap will be tightly mounted in the bottle.
To connect the air pumping unit with some device, you will need windscreen washer hoses, which, like a relay, can be bought at any auto shop. During operation of the device, you should carefully monitor the oil level, which prevents overheating. It should also be remembered that the compressor from an old refrigerator should not run longer than 45 minutes.
See also - Refrigerator freezes food: why is this happening?
How to check the wiring and connect a compressor from an old refrigerator without relays and circuits?
Many people are interested in connecting a compressor without a relay, and here there are significant nuances, information about which is quite difficult to find. It is not so much the scheme that is important here as the principle. First you need to ring the general conclusion, which is located apart, to the left of the other two. Having attached the terminal to the general output, you need to find the working winding with the second terminal. For example, one output shows 14 OM, and the second shows 37.9 OM. Which of these windings is working? Many people mistakenly claim that the working winding is the one that shows the highest resistance. But this is fundamentally wrong.
Important:
The working winding is the one that shows less resistance! And the one that shows more resistance is the starting (starting)! If you mix them up and connect the compressor incorrectly, it will quickly overheat and will not last long. Therefore, accuracy is needed in this business!
This is the rule that works for refrigerator compressors and we must not forget about it. The next mandatory preparatory stage before connecting is to check if any of the windings breaks into the case. Otherwise, it may happen that you touch the body of a working device and you will be shocked. And this is possible, because the compressor is not new. To check, you need to touch the output of the winding with the left terminal, and with the right one - anywhere on the case, test the second and third outputs in the same way. Only if the device has shown that all three outputs are reliable and do not puncture, it is possible to connect such a compressor to the operating device.
The next step is to use the terminal blocks to connect the compressor from the old refrigeration equipment to the voltage. First - to the common wire and to the worker. And the starting voltage will be supplied by briefly touching the bare wire. But you need to do this carefully and carefully so as not to get an electric shock. When voltage is applied, the compressor starts to hum, and when we touch the start output, it turns on and starts blowing air. The optimal operating time is 10-15 minutes, during this time some heating of the unit body is allowed, up to 50 degrees, but it cannot be allowed anymore.
See also - Is freon from the refrigerator harmful to humans
If the wiring is ok, the oil must be changed!
Of course, you can leave the old oil as well, but is it worth the effort to connect the old compressor to the new device for only a few sessions? Most likely, there is a long-term used oil inside, which contains metal particles and does not protect the unit from overheating well. It is best to completely drain the old oil and refill with new engine oil. Where to fill it is not a question. As a rule, a large bolt is clearly visible on the compressor housing, which must be unscrewed with a wrench. Through an open hole, the old is drained and new oil is poured.
How to extend compressor life?
Prevention of overheating and premature failure of the compressor is a sufficient amount of oil, the correct connection to electrical outputs and a limited time operation. It’s good to connect a capacitor between the common and starting outputs, especially if it was in the refrigerator. This simple device increases engine efficiency and extends its service life.
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Good day. Doesn't the compressor need a capacitor to start the compressor?
Most often needed, you're right.