How to test a compressor

[Tetrafluorometh]

I got 2 compressor's off eBay cheap! They are brazed shut which is a good start. I just want to test them to make sure they spin up.

So can i wire them up and flick the swtich for a few seconds with them still brazed up?

I need to get some 3uF cap's for them before i even do it

[blinker0]

Alot of people bump test them.. Haven't ever tried to do a sealed compressor myself

[ezgonzo]

as its a closed comp the best and the easiest way is to cut the end of one of the suctions and also cut the end off the discharge (if they've been capped of with coppper pipe with brazed ends ), then just fire it up if its got good pressure and suction alls ok, also check that theres no burney oily smell, once tested just crimp and braze the discharge then braze a schrader valve on the suction, then vac out for twenty mins or so, job done.

[ruffus]

i have done it i really don't think it is to much of a good idea but i have never had a problem but i would only do it for like 3 sec or less just so pressures don't build up on your discharge.

[runmc]

I would not do it if it was all sealed up. :shakes:

[yngndrw]

once tested just crimp and braze the discharge then braze a schrader valve on the suction, then vac out for twenty mins or so, job done.
Would it not be best to vacuum out from the discharge, that way it would evacuate all parts. (Due to the internal valves.)

[wdrzal]

You need a hermetic compressor analyzer & component analyzer...............One company's analyzer's are Called "Annie" A-12 THEY HAVE 3 analog meters on there A12 model, They have lights and toggel switches & meters to preform various tests,they contain internal capacitors (you just select closest range of 3) + check mfd(ul) of unit capacitors can run the compressor"temporarily",a voltage meter,ohms(checks windings,shorts,grounds, ,and current. With this analyzer you simply clip onto the 3 compressor pins and hit start. These analyzers also check capacitance,continuity(ohms),perform starting relay pick-up & drop-out voltage,and can even reverse compressor direction (to try to un-stick a stuck compressor)(usually pistons stuck @ TDC or BDC).

Best use is to start a bare bone compressor without needing capacitors or relays,a very good investment. Just be sure in that the seller give a garurentee that all 3 analog meters are working as intended. It's real easy to flip a wrong switch and send high voltage or current through say the ohms meter,ruining it. It's very important to follow instructions step by step,at least until you are real familiar with all the switches & functions.

I seen and purchased these on ebay any where from $25.00 to 75.00 and are worth there weight in gold ,since you can check all compressors functions, with the only exception I can think off is winding insulation deteration ,that's not shorted (,just starting to break down.You need a megger for that.)That's a more advanced test,most here probably never done and can be dangerious because of the high voltages applied.

If you would get a "annie" A-12 model ta- 1200 ,You can PM me ,I have a single 8x11" card(both side that walks you through all the tests.so don't fret if it don't come with directions.

They are for 120 to 240 volt single phase Hermetic compressors up to 30 amps.

There are other companies that make analyzers but for the DIY guy these can be had cheap and do everything the 300.00 to 500.00 analyzers do. There are some 3 to 1 plugs included that have clips on one end,you can easily make one if missing. clip onto commresor ,start ,run & common pins.

It plugs into either 120v or 240 volt and has a single D battery for the ohms test.

These are NOT for 3 phase.

Soon as I find the disk for my scanner I'll post the laminated card we keep in every unit. formatted my pc's and misplaced the multifunction disk. sorry. I have previously posted here so maybe a search using "annie" will turn up the instructions.

Many time we use a Robinair process tube adapter kit,they just clamp onto straight copper tube(various sizes included)(quick no brazing) with removable rubber compression seals along with a added compression gauge with high pressure relief valve to determine the condition of small used hermetic compressors.
We do this primarly to see if the valves leak and the compressor is capable of achieving the rated compression ratio.



If your in the USA & purchased this model analyzer I can copy,laminate & mail you the instruction sheet. Just PM me.
Walt,