Page 1 of 2

New Fridge Compressor!

Posted: Mon Sep 08, 2008 7:52 pm
by iisthemuffin
Hey i just got a fridge compressor! Im so excited! My uncle found it sitting in an alley by his house.

Im not sure whats going on with it though. I wired it up and plugged it in after fixing the pipes.

It runs for about 5 seconds, then shuts off.

Im not sure why

And yes it does suck in air and discharge air.

Any ides why this is happening?

I wasnt sure how to wire it though. It had a red, white, and 2 black wires.

I assume the white and red are positive and negative. And im not sure what the black ones are for. Im certain one must be ground. but which one. Or is it both?

Could it be shutting off because i wired it wrong. Oh please help. I would be so sad if my long awaited fridge compressor does not work

Posted: Mon Sep 08, 2008 8:04 pm
by TurboSuper
Well, it runs off AC, which means there really isn't any "positive and negative", you need to think of it as "live and neutral".

That being said, most AC systems will only need 2 wires and mabye a third for the ground...unless it's running off 3-phase power which I doubt. Unfortunately this is where my knowledge ends :?

Posted: Mon Sep 08, 2008 8:07 pm
by iisthemuffin
i understand neutral and live. Im on my way to going to school for electrical enginnering.

It was just easier to say the way i had and i was in a hurry. I still am.

And usually things on AC systems have a ground. Im confused as to what the ground would be. And if the 2 black wires are not ground what should i do with them

Posted: Mon Sep 08, 2008 8:09 pm
by TurboSuper
I found this on Google: http://www.davesrepair.com/DIYhelp/DIYcmprtest.htm

Seems like the one the guy had had a "run" and "start". Mabye one's the "start" and the other the "run", where the two black wires are neutral returns for each?

Posted: Mon Sep 08, 2008 8:10 pm
by iisthemuffin
Makes sense.

Im on google now as well. Ill give your link a read.


Seems to be a good link. But unfortunately i do not have the toold required to test it. Im going to try and read though it and see if i can figure something out without testing the leads.

EDIT - I unhooked the ground from the black wire i had it hooked to and it ran steady without stopping. Im Still confused about the black wires.

If anyone who has built the fridge compressor, i would like your input on the 2 black wires.

Posted: Mon Sep 08, 2008 8:49 pm
by rp181
try connecting the black wires together, im thinking its 1 of these two:

1) its just ground, with a wire coming out to connect to another part of the fridge, probably the chasis.

2) Its a control for tempeture, the fridge stops it when desired temp is reached. Try connecting red and white to AC, touch the black wires together, and disconnect them.

Posted: Mon Sep 08, 2008 8:56 pm
by iisthemuffin
So if it were temperature, from what your saying, when i touch the two black wires together the compressor should shut off correct?

Also there is oil coming out of the air outlet. Should that happen? Why is it happening? How do i stop it if it should not happen?

Also do i need to put oil in somewhere every so often?

Posted: Mon Sep 08, 2008 9:47 pm
by hi
thats probably why it was sitting in an alley...

Posted: Tue Sep 09, 2008 3:15 am
by Brian the brain
Nope. it has a switch, wich looks like a small silver circle.This shuts it down.
remove this part and connect it directly and it will run withut a problem.
Furthermore, it's just a tiny piston compressor inside of a bucket submerged in a bucket of oil.
Tilt it and it will spew out the exess oil.

Posted: Tue Sep 09, 2008 7:32 pm
by iisthemuffin
Brian. I hooked it up to white and red wires and it runs fine. I did not have to remove anything. Is the way i have it hooked up ok? Or would it be best to do what you said?

Also, if i tilt it on its side, wont that jsut put more oil into the air line?

I drew up a quick sketch to help with my wiring dilema. The red wire is obviously the live wire, as it has the switch between it and the wiring harness.

Then im still assuming that the white wire is the other wire for power. But then, i still have the two black. WHAT ARE THESE? Its bugging the crap out of me man.

Even if they arent important i would love to know what their purpose is

Posted: Wed Sep 10, 2008 6:09 am
by TurboSuper
If you took an ohmmeter you could probably find the coils and how they're arranged, mabye that would demystify the black wires.

Since you're going to a school for electrical engineering, a simple multimeter may not be a bad purchase if you don't have one already.

Posted: Wed Sep 10, 2008 11:29 pm
by POLAND_SPUD
I am back...

first of all there are several possibilities here.. so do not take anything as 100% sure

+these things normally have problems with starting up. Mine runs for up to 5 seconds then it stops and then after ~15 seconds everything repeats..... all in all it takes ~ 2 minutes for it to warmup enough to run continously....

+firdge compressors (and probably AC compressors as well) have a circut which doubles the current going to the electric motor when the compressor is starting up. There is a possibility that one of the extra cables has something to do with it....


now the best thing you can do is to do what turbosuper said... and check how the compressor was wired when it was still a part of a window compressor.

Posted: Thu Sep 11, 2008 8:31 pm
by iisthemuffin
This is an actual fridge compressor POLAND.

But i no not have the proper equipment yet. I will not be going to school until sometime next year.

By the way, you are just the man i was hoping to reply in my topic. I have a few questions for you. Would you rather me PM you or just ask them here since it would be completely appropriate for this topic anyway.

Well get back to me man.

Posted: Fri Sep 12, 2008 7:52 am
by POLAND_SPUD
well write it here.....
at least others can contribute or help


the easiest way to find out how to hook up a fridge compressor is to check how it was wired when it was still a part of a fridge... really...

check where all the cables were/are going and find out what these two black cables were supposed to power




oh yeah sorry I had very little time (work :?) to replay to both your post and the other one (about an AC compressor) when I wrote my last post so I acccidentally mentioned AC in yours

Posted: Fri Sep 12, 2008 1:26 pm
by psycix
Ive heard of oil coming out of the air outlets more times, it is normal and will probably stop doing that in some time.
Just make sure that it does not spit oil into a cannon.

If it runs just fine without the black wires, cut them off and insulate.