Pressure switch doesn't kick off.

by Scott
(Colerain, Ohio)

The pressure switch does not kick off when the compressor has reached its maximum pressure. The contacts weld together. The switch was burnt up and was replaced as does the same thing.

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Scott, it's odd that you had the same problem with two pressure switches. Really odd.

You don't indicate your compressor voltage, but I assume you got the pressure switch that suited the voltage?

That being the case, I suspect a faulty re-wiring. Is this possible?

Bill

Comments for Pressure switch doesn't kick off.

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Oct 13, 2015
Wiring pressure switch
by: Bill

Please take 4 closeup photos of how you've wired the pressure switch - from each angle.

Start a new thread. Title the thread "Pressure switch doesn't kick off - Sam's comment" and I'll move the images to here.

I and all visitors that care to will have a look, and we'll see if we can figure it out.

Oct 13, 2015
Compresser not shutting off at 125lbs.
by: Sam

This is the second new switch Ive put on it. on the line in terminals I have the black wire on the left and the white wire on the right. On the motor terminals I have the black wire on the left side and the brown wire on the right.

Oct 13, 2015
Bum switch?
by: Bill

If it's supposed to shut off at 125 PSI, and the tank pressure is getting to 150 PSI and you have to shut the compressor off manually, either the new pressure switch is wired incorrectly or you have a bum switch.

Oct 12, 2015
Switch not cutting at 125lbs.
by: Sam

I just installed a new LEFOO pressure control and it will not cut out at 125lbs. It says it is factory set to that number. The air just keeps going up until it is close to 150lbs and shut it off manually

Jul 30, 2013
looking for the right pressure switch for Craftsman 106.154780
by: Mark

Bill, my new (old) compressor pressure switch didn't come with a cover and does not seem to work at all.

(originally the line and motor wires where on a single terminal, when I separate them the voltage never makes it to the motor side.)

The problem that I am having is understanding what Pressure switch I should replace it with because the cover on the old one is missing.

This is on a Sears Craftsman 150 psi twin cylinder unit. Model# 106.154780 20 gal. I picked one up that is a 95/125 but I think that would over limit a 150 psi unit...right?
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Do you recall what the cut in and cut out settings on your old switch were?

That your air compressor can produce 150 PSI doesn't mean you use air at that level. Your regulator knocks the pressure down to the right level for your air tool, so it does not necessarily follow that using a 95/125 switch would cause you problems.

I cannot provide specific electrical advice as I am not an electrician. It seems odd to me that your old switch had line and motor wires on the same post. I wonder if that might have been the ground you speak of?

Regardless, take your old switch with you when you go to the compressor parts store, and find one that looks similar inside, and has close to the same settings, or has adjustable settings.

Newer switches have the line and load (motor) terminals clearly marked, and often there is a diagram under the switch lid.

Did you contact Sears to see if they had a current switch for you?

Bill

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my compressor does not have a pressure switch and it keeps working and it does not cut out is there any danger...

by Ely
(central america)

my compressor does not have a pressure switch and it keeps working and it does not cut out is there any danger to that what shuould I do

should i keep working it that way

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Bill says...

Ely, if it were me, I would not use an air compressor that did not have a working pressure switch.

The pressure switch is the first level of air compressor safety, preventing over-pressurization of the compressor tank and plumbing.

The second level is the PRV.

If the PRV should fail, and your pressure switch is not working or absent, it could have catastrophic results.

Let me be clear. If the compressor runs without a pressure switch, and the PRV fails, and the demand for air is not greater than that which the air compressor can put out, you or a fellow staff member could be hurt by debris if a pipe or the tank lets go.

Good luck,

Bill



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