Pressure switch contacts keep burning out.

by JB Johnson
(Sidney, Ohio)

I have a 5HP Sanborn air compressor that keeps failing the pressure switch every month or so. I am on my fourth in the last year. The switch will stick "ON" because the contacts will burn and weld together.

Comments for Pressure switch contacts keep burning out.

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Aug 13, 2017
Pressure switch contacts burning out
by: Doug in s.d.ca.

You're welcome, Paul.

Emory cloth is good stuff.

Please keep us posted on what happens next.

Thanks.

Aug 12, 2017
Contacts burning out
by: Paul

Thank you, Doug. We will have an electrician around in a couple of weeks and I will ask him to check those things out, and see what he thinks of a Mag starter. Meanwhile I hit the contacts with some emory cloth and that seems to have worked for the moment. I also bought a new one and have it on the shelf for when this one next fails....

Thank you!

Paul

Aug 03, 2017
contacts keep burning out
by: Doug in s.d.ca.

Paul -

No sweat, milk and harvest first.

Not sure, really, about plain 23474653 vs -A vs R.
But they seem to be for different IR 230V 5HP compressors - So I ask for your model number again.

Anyway, it may be the wrong switch, or there may be some other problem.

Are you usually nearby when the compressor starts? I'm thinking intermittent check valve or something causing hard start.

Can you measure the start and run current?

Have you checked that the start cap is being switched out when it should?

Are both contacts burning/welding, or just one?


Aug 02, 2017
Pressure switch burning out
by: Paul

Hi Doug,

It is a 5 HP 230 v. I just looked inside the cover of the switch and it is an A. Maybe I have been using the wrong one?

Also- sorry to be so slow in responding- we are a dairy and I have been on a tractor almost continuously for the last 4 days, making our second cut of hay.

Thanks for your help,

Paul

Jul 27, 2017
23474653-A?
by: Doug in s.d.ca.

Or is it 23474653 R you've been using?

Jul 27, 2017
Pressure switch contacts burning out
by: Doug in s.d.ca.

Paul -

I doubt anyone sells the contacts as a repair item.

But please tell more about what it's controlling. That is, the HP and voltage of the motor.

It sounds to me that your machine "deserves" a mag starter, which is essentially a low power relay that closes BIG contacts which actually turn on the motor.

I think that would be a permanent solution and eliminate the 100 dollar replacements...

Jul 27, 2017
Find replacement contacts for IR air compressors
by: Paul

Hi Bill,

Every 2-3 years the contacts go on our IR 2-stage reciprocating upright compressor, pressure switch model 23474653-A. It is on a 10-guage cord running about 5' from the panel, so I don't think there's anything wrong with the wiring. Also we have replaced the capacitors, most recently about 6 months ago. My question is whether you know of any place to buy replacement contacts. I tried calling Hubbell (the manufacturer) and they won't sell them because the switch is proprietary to IR. IR won't sell them because they don't have them; they only buy entire switches. Any thoughts? Aside from the waste and expense of replacing a perfectly good switch, replacing just the contacts would be WAY faster and easier.

Thank you,

Paul

Apr 22, 2017
Testing capacitors
by: Bill

You go to the page on this website titled testing capacitors!

It's linked from the sitemap page under Capacitors.

Cheers.

Apr 22, 2017
Points sticking
by: Anonymous

How do you check the capacitor to see if it failing?

Aug 19, 2015
contacts
by: Doug in s.d.ca

Do you have a specific model number?

In addition to what Bill asks, you may want to check the motor capacitors - possibly one is failing, causing excess amperage.

Aug 19, 2015
Compresssor contacts keep burning out
by: Bill

What's the supply amperage, distance from power source to compressor, and ratings for the pressure switch you are using, please?

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