air compressor hard start

Sounds like a handy fix, but I don't quite get what's happening, here. Does your CO₂ cylinder just effectively increase the volume of your receiver?

I don't know much about pneumatics, but the statement "Remove the safety vent ..." makes me think a bit.

I don't think he's got rid of the safety vent, but re-installed it on a branch of the T.

Codey

I guess that's OK, as long as the T & pipework are all rated above the safety valve release pressure.

Good point. The primary safety valve is set at 30 psi and is brass. I used a bronze nipple and "T" to be on the safe side. Griff

Yes the Co2 cylinder provides a space for the initial volume from the primary cylinder to accumulate while the motor gets up to speed. The safety vent is to be installed in one side of the "T" and one side to the tank. Griff

I HAD an air compressor that when cold tripped the motor safety.

How cold? Mine does it too but at -10° F and below?

I don't get that cold but this fix should work. You may need a larger co2 tank to give more time for the motor to get up to speed. Griff

I have operated compressors that used what I think is a similar setup to load and unload a continuously running compressor. The machine had a "clearance pocket" that was valved out from the cylinder head when the receiver needed air and valved in (i.e. connected) to the cylinder space when the receiver had reached its setpoint. The advantage of using this clearance pocket volume was that the air in it acted as a spring to assist the downward motion of the piston, thus reducing HP use even more than what wasting compressed air would have. Though the compressor to which I refer was double acting I think you are seeing some "air spring" effect. The v/v ratio may be just right between the cylinder and the CO-2 cylinder.

You haven't told us what causes the problem yet. Yes, you have "fixed" it so it will work, but it should run from the factory.

What is too small on it from the factory that is causing the problem when it is a little cold out, Griff?

Ken

It was cold and I didn't have enough current to start a cold compressor. A goof on my part was wiring the shop with #6 wiring. Griff

Hello, It depends on the temp. could be oil viscosity, or piston ring to cylinder interference, or wear. Also it could be the motor start cap/circuit, voltage sag. or even just trying to start against the head pressure. Some starter pressure switches have a check valve setup to bleed off the pressure between the compressor and the switch so it does not half to start against a load.

But if its working for you now that great. But you could be the hidden problems that will sooner or later show up.

Charles

From the get go I have had this problem do to wiring with only #6 wire. The voltage would drop to 177V from 240V. Had to do something. Griff