Blown compressor capacitor??? Help

[mm man]

Just got my mini ready for paint and boom goes the compressor
Can any one help it’s a 4 hp twin pole 240v single phase motor . I fitted a new capacitor and that lasted 1 minute then boom . Can any thing other than the motor cause this to blow abit reluctant to buy a new motor if something on the compressor would cause it to blow ?? Pump it free moving ! And when it blow yesterday there was no pressure in tank as it only ran for less than a minute .
Help please as mini is desperate for it’s top coat .

[VTEC JON]

Hi, I work on compressors everyday, the capacitor you fitted was it the same micro farad rating?, if so I would say that you need to get a rewind of the motor, sounds like there is a problem with the windings, there is nothing else that would cause the capacitor to blow.Don’t know where you live but I’m sure there will be a Motor rewind company local.

[mm man]

Originally Posted by VTEC JON

Hi, I work on compressors everyday, the capacitor you fitted was it the same micro farad rating?, if so I would say that you need to get a rewind of the motor, sounds like there is a problem with the windings, there is nothing else that would cause the capacitor to blow.Don’t know where you live but I’m sure there will be a Motor rewind company local.

Thanks for your reply
It was rated 90uf and the one a local compressor shop got me one rated 80-100uf — 250v
The plate on my motor reads 90uf — 450v ?
Should the one I fitted be 450v ? even tho it on a 240v 30amp ring
Again thanks for your help

[stun538]

The 240v rated ones are usually just used for starting the motor and are switched out at 2/3 ish of full speed. You need a 450v rated capacitor

[mm man]

Originally Posted by stun538

The 240v rated ones are usually just used for starting the motor and are switched out at 2/3 ish of full speed. You need a 450v rated capacitor

Thanks so would this new one of blown because it was 240v ? Only ?
Or because of another issue with the motor as said before ie windings

[gadget555]

I had a similar problem a couple of years ago, blew the capacitor replaced it like for like and it blew again, I found it cheaper to replace the 3hp single phase motor than get it re-wound.

[mm man]

Thanks for the replies it now looks like the shop gave me the wrong capacitor they gave me a 250v start one instead of a 450v start and run type . I had taken the motor apart away to have a look at the widings no black marks and no burnt smell so the shop is giving me the correct type ( free of charge there mistake)and fingers crossed.

[mm man]

Fitted a new 450v start and run capacitor and look what happened






TOP COAT !!

[stun538]

Nice!