Horse agistment – bar fridge not working

The bar fridge down at the horse agistment that we use for storing carrots (horses like them) has decided that 2011 is it’s last year of operation. No complaints it must be over 20 years old.

Do we try to fix or just buy another one?

The fridge is behaving abnormally, one day the carrots were icing up and other occasions the fridge was not running, defrosting with water in the bottom – thermostat?

The round thing is the compressor and mounted on the side is a box that contains the compressor relay and a overload protector. To the right is a terminal box, some wires from here run up inside the fridge to the thermostat. Just below on the table is the cover for the relay box. A multimeter is all I should need to test the components. 

The relay just pulls off the motor terminals and checks with the multimeter confirms that it is OK.

We need to take two sets of readings, with the relay upright in normal position we should get zero ohm readings.

Flipping the relay over should give infinity readings – it checks out OK. The overload protector should give zero ohms and also checks out OK. It's surprising how reliable compressors are but they still get a bad reputation. Some compressors use a start capacitor, this one has start and run windings which read OK. Let's move on…

 

This is the terminal or junction box, the relay/overload wires terminate here and are extended up inside the cabinet to the fridge temperature control (thermostat).

Not much to go wrong here but checked the crimp connectors anyway.

 

To reiterate, when the fridge started giving trouble I noticed a couple of things, one morning the carrots were nearly frozen and other days the fridge was not running with water in the bottom.

There are three wires, red is 240V in and the white controls the compressor relay, the other wire is earth. With this fridge the capillary tube is folded back on itself right at the end and secured to the bottom of the freezer box with a small plate and a couple of screws.

The thermostat should normally read zero ohms and after about half an hour in a fridge freezer it should read infinity.

The initial tests were OK but I suspect this thing is intermittent so I repeated the tests over a period of time, pretty boring but needs to be done.

Patience paid off the thermostat is definitely intermittent so I’ll have to go looking for a replacement.

Off to try and purchase a replacement thermostat, went to two or three places with no luck and finally walked into a appliance repair shop where I had a good feeling, the walls were covered with replacement parts!

Nice lady looked at the thermo, disappeared into a storage nook and came back with the above, checked the contents with the original and very similar so fitting should not be a problem. Purchased for a fair price of $39 bucks.

Update 3th Feb: Fitting the generic replacement turned out to be more troublesome that I had expected. For a start the capillary tube was much longer than the original, the replacement is for a standard single door fridge so I had to neatly coil up the excess and tuck behind the freezer box. Next the supplied universal mounting bracket was to long and fouled the plastic cover, so I had to trim with tin snips etc. The original thermo mounted with the spade connectors facing up so I did the same with the replacement one but the connector wiring again fouled the plastic cover so I had to turn it the whole thermostat upside down!