Compressor thermostats..

[Pandrone]

Today i began making my vacpump, This would be made of 2x Danfoss TL4A 1/8hp R12 compressors. Well the first one worked fine. Then the other one that had another startingrelay but i took of all the thermostat cables going to the relay and started it. It worked but after a while it = much white smoke from the relay. Now i tested to take the Brown cable from the thermostat and wire it together with the black from the thermostat. Fired it up: Worked like a dream for a couple of seconds then the smoke again. How should i wire it to make it work? I can provide images of the relay and thermostat if you want.

[Pandrone]

Originally posted by pc ice
im suprised it keep's starting.

Hehe :D. I don't have a clue of how to wire it correctly. So i'm just testing around for now.

[Pandrone]

Originally posted by pc ice
i can take some pic's of my compressor wired up. '

That may help :).

[Pandrone]

Heres the wiring i use :D.

The one that doesn't work: Big Image (http://upload.stormaz.servebeer.com/index.php?bigimage=Kompressor%2Ftl4anew.jpg)


Heres the wiring before i touched it: Big Image (http://upload.stormaz.servebeer.com/Pandrone/kompressortl4a.jpg)


Heres the older compressor:
Big image (http://upload.stormaz.servebeer.com/index.php?bigimage=Kompressor%2Ftl4aold.jpg)


Ps. Didn't understand that much from your wiring.

[Gary Lloyd]

Hmmmmm... The old compressor is exactly the same and it works. Why not wire it exactly the same as the old one? But then it probably won't work, because you have let the smoke out of the relay. The smoke has to be kept inside it to work right.

Still, its worth a try. :D

Then, when you are done screwing around, replace the relay and hope that the compressor windings are not burned out.

[Pandrone]

Originally posted by Gary Lloyd
Hmmmmm... The old compressor is exactly the same and it works. Why not wire it exactly the same as the old one? But then it probably won't work, because you have let the smoke out of the relay. The smoke has to be kept inside it to work right.

Still, its worth a try. :D

Then, when you are done screwing around, replace the relay and hope that the compressor windings are not burned out.


Gary, the two compressors does not have the same relays. Theres a few numbers on the markings thats not same :).

[chilly1]

Try this ...
Build one of these, it is called an annie. It is used to substitute for a start circuit. the switches should be rated at 20 A and the momentary switch should be held down when power is applied and quickly released when the compressor starts. This should be used in conjunction with an Amp meter on the common lead. You should also install a fast blo fuse sized at the locked rotor amps (LRA) of the compressor you are testing.
http://www.blairwing.com/images/startsub.jpg
EDIT,, These terminal positions are correct for most of the danfoss compressors but wil be different on some other models
so make sure you know which terminal you are connecting to.

[Pandrone]

chilly1: Thanks for the tip. But the capacitor, is that really neccesary?(maybe a dumb question) But i haven't seen any capacitors on the compressors i've mounted of fridges.

[chilly1]

No the cap placment is optional a lot of larger compresors use them my placment of this in this circuit is so it can be used with all.
Install a jumper in its place. If you build this in a small box with a dedicated plug and aligator clips for the leads you will have a test rig for all compressors that draw less than 20 A locked rotor.

[Pandrone]

Also: What can i pressuretest my system with if i cannot obtain nitrogen(not that i cannot, but the regulator is damn expensive)? I have acess to Argon, CO2, Mison, and some other gases(what my father has home). And also does the regulators form the C02 bottle fit on a nitrogen bottle or do i have to buy a new regulator if i borrow a Nitrogen bottle?

[chilly1]

The argon regulator will fit the nitrogen, a co2 regulator is designed for a lower pressure and will possiably rupture with nitrogen, Argon is a good alternative to nitrogen, co2 is ok to use as an inert gas for welding. But Co2 cannot be used to weld in a compressor, if the compressor is in the circuit then you will have to use a gas that is not misiable with the oil. co2 will mix with the oil and be very hard to get out...Argon or nitrogen is always acceptable for welding on a refrigerant circuit.