Faulty Compressor Pressure Switch?

[Glenn F.]

The other day my trusty old two stage Quincy, which is set to shut off at 163# went up to 176# and shut off. This has never happened before. Pump and motor turn freely and neither were hot to the touch. I assume my pressure switch is faulty? Is such failure common? Of course I can/will buy a new switch if necessary but assuming mine is sticking is there any way to free it up and be reliable again?

Thank you,
Glenn F.

 

[jniolon]

check the contacts in the switch to see if they are sticking

john

 

[JD Dave]

Yes, pressure switches can go south. I would replace the switch.

 

[wp6529]

Check your pressure gauge as well before you assume the pressure switch is bad.

 

[Welding man]

The other day my trusty old two stage Quincy, which is set to shut off at 163# went up to 176# and shut off. This has never happened before. Pump and motor turn freely and neither were hot to the touch. I assume my pressure switch is faulty? Is such failure common? Of course I can/will buy a new switch if necessary but assuming mine is sticking is there any way to free it up and be reliable again?

Thank you,
Glenn F.

I have a 7.5 HP compressor. It gets used 8 hours a day 5 or 6 days a week. I have to replace the pressure switch and the magnetic contactor about once a year. I keep one of each in stock at all times.

 

[caterpillar guy]

I'd check the gauge also then do the switch if the gauge is good. I would also go to 175 for the pressure but that is just me with truck tires to deal with. 120 on the tire needs the higher pressure so I don't get stuck between the off and on spot in the pressure.

 

[Dusty MI]

I have a 7.5 HP compressor. It gets used 8 hours a day 5 or 6 days a week. I have to replace the pressure switch and the magnetic contactor about once a year. I keep one of each in stock at all times.

What size magnetic contractor are you using? Maybe you ought to be using a larger one.

Dusty

 

[John T]

One possibility is the pressure switch contacts are burned and sticking. While I have seen people try to clean them up once the coatings are removed they aren’t the same and can stick again so I’d go with a new switch

Is the switch rated for your compressors HP ??? And as others stated insure your pressure gauge is accurate ?

If it consistently does work and shuts off at the same pressure regularly maybe adjust the switch ??

See what the electricians have to say

John T

 

[stevieb49829]

Take a close look at the guts of the switch. Sometimes crawly things get trapped between the contacts as they trip. Carpenter ants come to mind. BTDT. steve

 

[Brownie450]

Check for rust or other blockage to the switch from the tank.
New switch is always a good idea.
Check the safety valve while you're at it. The shop up town
had the safety valve stick once & it took most of the back
end of the shed out. Luckily it happened at night. I always
shut ours off for night.
Jim