How to wire in the pilot valve on an Atlas Copco LE7

by David Zahn
(Parma Ohio USA)

Atlas Copco LE7 80g air compressor

Atlas Copco LE7 80g air compressor

Atlas Copco LE7 80g air compressor
Atlas Copco LE7 80g air compressor unloader
Atlas Copco LE7 80g air compressor control panel

I have an older Atlas Copco LE7 80g air compressor running with a 5HP 1PH 230v motor. The unit has a separate motor starter (2Pole contactor with OL and 2 NC/NO control switches.)


It also has a large unloader valve which is actuated with a pilot valve. The Pilot valve is a ASCO 8314C53 which I have 2 of (120/60 and a 230/60). I had bought a replacement for it but didn't see the voltage rating of the one I bought. Both valves work.

The compressor also has a 2Pole pressure switch.

The problem is that I don't have a wiring diagram for this compressor and I am not sure how to wire in the pilot valve so that it will open upon startup (actuating the unloader valve) and then closing upon full start so that the tank can fill.

Any help would be greatly appreciated!

Also, Please ignore the wiring in the photos. I was just trying to get it to run and was manually powering the pilot valve.

Comments for How to wire in the pilot valve on an Atlas Copco LE7

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Nov 04, 2016
Problem Solved
by: David

I completely removed the unloader. I then put a check valve to the main tank. and between the compressor and check valve, I have a tee with a 1/4 valve blowing off at a small amount. This allows the line to depressurize but the tank won't leak because of the check valve. The amount that the valve blows off is small enough that it doesn't effect how quickly the compressor fills the main tank. Here is a diagram


[compressor]-----[tee]-----[check valve]-[tank]
|
[valve]

Nov 03, 2016
What did u do? I have the same problem.
by: Anonymous

What did u do? I have the same set up, same problem. thank you

Oct 05, 2015
solved
by: david

Problem solved. Thanks

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