Air compressor not running

[Jonny J]

Hi guys
I have purchased a second hand sealey air compressor that isn’t running. Got it home and started to check it out to find that the capacitors are missing from the motor. It’s a 2.2kw 3hp motor. I did some research on the internet and I think I need 2 capacitors, start capacitor and a run capacitor. Can anyone tell me what size of capacitors I need?
Thanks

 

[TripleSix]

Is there a plate on the motor?

That should list the required capacitance.

 

[A1an]

Its almost identical to my SIP unit.

Il open it up tomorrow and check the caps if that would be of help.

Might even have a couple in the 'spares' box

 

[Jonny J]

This is the only plate i see which is on the plastic lid for motor. It’s not very clear!!

 

[John]

Id like to know as well as I have one with the same problem.

Cheers John

 

[Jonny J]

I have had no luck yet. I was told that i need a start capacitor of 70uf 450v with a built in circuit breaker and a run capacitor of 60uf 450v. Having a bit of trouble finding them. Any of you guys know where you could buy them?
Thanks

 

[Barleymow]

I had a small compressor that wouldn't start .couldn't get it to start so bought another. Removed hose from old one was a his tank was full hence wouldn't turn on

 

[ROBINWORKS]

https://uk.rs-online.com/web/p/polypropylene-film-capacitors/9084234/
https://uk.rs-online.com/web/p/polypropylene-film-capacitors/7600045/

 

[A1an]

Sorry for delay.

 

[bigg6480]

Call sealey parts I have always found them very helpful. I thing the number is on the web site.

 

[Jonny J]

Just an update. Got in touch with sealey and they were looking over £200 for the capacitors!!! I just bought a new motor for £100 and compressor is going fine now. Thanks for everyone’s help

 

[A1an]

Just an update. Got in touch with sealey and they were looking over £200 for the capacitors!!! I just bought a new motor for £100 and compressor is going fine now. Thanks for everyone’s help

RS Components would supply you with the caps for £20ish a piece
Well done on the fix though.

 

[Mursal]

Yes a 30 microfarad and a 100 microfarad capacitor will get you away both 450V.
(The funny U =micro)

You'd then have a spare motor ........

 

[Hard Graft]

https://www.maplin.co.uk/p/30f-440v-motor-run-capacitor-rg69a

 

[Philip Watkins]

Yes a 30 microfarad and a 100 microfarad capacitor will get you away both 450V.
(The funny U =micro)

You'd then have a spare motor ........

You mean one of these µ

 

[Mursal]

Greek I believe?
A lowercase mu if I remember correctly .......

 

[Pheasant Surprise]

Just an update. Got in touch with sealey and they were looking over £200 for the capacitors!!! I just bought a new motor for £100 and compressor is going fine now. Thanks for everyone’s help

Wow £200 for caps!! I guess some mothers do av em!

 

[Pheasant Surprise]

Greek I believe?
A lowercase mu if I remember correctly .......

We owe a lot to the Greeks. I think they owe a fair bit now themselves.

 

[Pheasant Surprise]

Yes a 30 microfarad and a 100 microfarad capacitor will get you away both 450V.
(The funny U =micro)

You'd then have a spare motor ........

Found a couple of online cap-start and cap-run sizing calculators online, but they appear to be North America focussed 110v etc for sub 5hp single phase motors.

 

[Jonny J]

The reason why the capacitors were expensive from sealey was because one of the capacitors has a circuit breaker built into it as the sealey motor did not have a centrifugal switch built into it. An ordinary capacitor would not work on this motor. So i was told!!