fault finding compressor

[kayl]

http://xtremesystems.org/forums/attachment.php?attachmentid=17493
i found this 10,000 btu compressor on the side of the road on rubbish throw out white goods day.
i have rewired the compressor and it runs for about 5 secs then trips the mains.
i have cut the pipes short so no restrictions?
(it had a service access vale, and the pipe had been cut so it must have ran out of gas in the past.
do you thinks that its well :confused: f#@ked

[Juicy629]

capacitor...check the amps..if its around 15 or so then its bad

[kayl]

:worship: ill have to check that, yes that could explain a few things, mains line is 10A here so ill have to check that cheers.

[Juicy629]

dont thank me...thank chilly..his info..my education ;)

[chilly1]

It sounds like there is more going on here than a bad cap. If you have a analog meter (one with a needle) that has about 10,000 ohms per volt resistance, put it on the ohms times 1000 scale and remove the capacitor from the circuit. Use a screw driver across the cap they can store deadly charges of voltage. Connect the leads of the ohmmeter to the cap if it is good the needle will go to zero and then gradually climb to infinity. This is because the capacitor is charging up the plates from the current supplied by the meter and as the potential balances the meter reads less flow of current.
I think the compressor has shorted windings as the compressor heats up the windings move, but it may be another issue.

[kayl]

i only have a digital cheap one.
i stuck it on the 20M range in ohms short cap leads to gether.
it went 0 . ......... . . . 20sec. 2.23 M ohms and the (.23) increases about 0.04 per second and keeps going up.
the two leads that went to the compressor measured 10.3 ohms
what should i check next?
or is the compressor dead

[chilly1]

Ok the capacitor is nothing more than two plates (remember Ben Franklin and the leyden jar?) that get alternately charged and discharged as voltage is applied . So when we attach the meter we charge it up as it charges the meter will reflect the fact that it's voltage more closley matches that of the meter, at balance current flow will stop. With no current flow there will be only a reading of infinity.
Check the three leads on the compressor to the others. Like S-R, R-C, C-S... (Run Common Start) Then take a reading to the case make sure it is a bare metal and post all four readings. We know the capacitor is good or somewhat...

[kayl]

ok here are the results sorry im too lazy to type it out.
basically r=red etc
and the stuff at the bottom is colour wire to ground
(i did it to the copper pipe for ground, case or compressor was open circuit to wires)

http://xtremesystems.org/forums/attachment.php?attachmentid=17681

http://xtremesystems.org/forums/attachment.php?attachmentid=17680

[chilly1]

Did you disconnect the wires from the compressor?
Check to the metal of the compressor with all the leads off the compressor>.. Thx.

[kayl]

ok
i see to right with out it running through the overcurrent bit to the left.

ok
c(r) 1.4ohms to gnd (red wire position)
(R) 1.3ohms to gnd (black wire position)
and (s) 9ohms to gnd (white wire position)

[kayl]

this thing is weird look at this is this a oil cooler or something?
http://xtremesystems.org/forums/attachment.php?attachmentid=17684

[chilly1]

The compressor isn't any good and there isn't anyway to repair it.. sorry.:(
That is a weird oil cooler... Must be a GE.

[Redwolf]

Nasteh burn out there :(

[kayl]

k thanx
so im guessing they should read open cct to gnd.
there are some parts i can use though.
this thing runs dual captubes to the evap.

[chilly1]

The capacitor value on a 10,000 btu is usually between 15 and 35 depending on motor design.

[kayl]

thanx i will have a look at all the compressors and see if i find something in that range.