Sealey compressor still not right

[Vixerfixer123]

Hi folks,still having trouble with my 3hp sealey.it will pump up to around 70psi and either trip the thermal motor switch or the breaker in the board.its had 2 new capacitors,new thermal switch,fresh oil.checked the check valve,had the lid off and cleaned reed valves etc.i took the belt and the motor will run no problem.what doesn’t seem right to me judging by info on youtube,is that the run cap is 65uf and the run cap is 60uf.i was led to believe the start cap should be around 3 times greater than the run.im out of ideas now‍

 

[jo1010]

Has your new start cap got a built in circuit breaker? Did you get the caps from sealey ? (Expensive!)... If not check you have the right ones .......I don't think the start vs run values are always vastly different ....but start can be slightly higher (I've seen 70 start/ 60 run)

 

[Vixerfixer123]

Has your new start cap got a built in circuit breaker? Did you get the caps from sealey ? (Expensive!)... If not check you have the right ones .......I don't think the start vs run values are always vastly different ....but start can be slightly higher (I've seen 70 start/ 60 run)

Not got a built in breaker,and got the caps from Amazon.

 

[Turbo]

The capacitor size is usually on the motor plate.

 

[jo1010]

Have a look at this thread - the capacitor values they talk about are different to your quoted values

Air compressor not running

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!! They probably source the start...

thefarmingforum.co.uk

Have you checked if the new capacitors are still ok or has the motor blown them already by any chance? Do both the motor windings meter out as good? Do Sealey supply caps rated the same as yours as spares?

 

[Vixerfixer123]

Have a look at this thread - the capacitor values they talk about are different to your quoted values

Air compressor not running

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!! They probably source the start...

thefarmingforum.co.uk

Have you checked if the new capacitors are still ok or has the motor blown them already by any chance? Do both the motor windings meter out as good? Do Sealey supply caps rated the same as yours as spares?

Oh right,that explains it then.i did take the motor apart not long back and was confused why i couldn’t find a centrifugal switch.

 

[Vixerfixer123]

I can’t understand why it used to work ok though,and now it don’t ‍.tried a google search and sealey website and cannot locate such capacitor with built in circuit breaker,but the motor definitely does not have a centrifugal switch.im going to try running it on the 16amp supply shortly.

 

[Vixerfixer123]

Can anyone tell if all this wiring is correct by the photos.its how I bought it.

 

[Misterg]

it will pump up to around 70psi [...]

Taking a different tack - are you confident that the pressure gauge is reading correctly?

 

[Vixerfixer123]

Yep it’s reading correct.it takes just over 2 mins to reach 70psi and when it shuts off,it trips the motor switch and there is no hiss from the pressure switch.

 

[Turbo]

Can anyone tell if all this wiring is correct by the photos.its how I bought it.

There looks to be a switch in line with one capacitor which could be a centrifugal switch.
There is also a current sensing relay used on motors that pulls in the extra capacitor when the motor current gets too high. It does the same job as a centrifugal switch but electronically. Normally only seen on expensive motors.

 

[Vixerfixer123]

There looks to be a switch in line with one capacitor which could be a centrifugal switch.
There is also a current sensing relay used on motors that pulls in the extra capacitor when the motor current gets too high. It does the same job as a centrifugal switch but electronically. Normally only seen on expensive motors.

I’ve just fired it up again,and it stuttered slightly then cut off,then third time it’s now working as it should

 

[knighty]

That sounds like a bad connection somewhere... you poking around gas moved it do changed how it acts

 

[carbon]

As mentioned by @jo1010 the start cap must be the type that electronically disconnects rather than a standard run cap. Post pictures of the cap markings.

Running a motor with the wrong capacitance will increase the current load and thermal overload will trip as a result.

 

[carbon]

If you still have the capacitors you replaced add pictures of those markings as well

 

[jo1010]

This is an example of a circuit breaker - its like a start capacitor but it performs like a switch?

70 uF capacitor with electronic circuit breaker | CEM

Optimise the operation of your single-phase motor with the 70 uF capacitor and electronic circuit breaker. Learn more about CEM!

www.cem-elettromeccanica.com

 

[Vixerfixer123]

These are the two new ones,but looks like after finding more info out about the compressor,one of them maybe wrong‍

 

[Vixerfixer123]

White one is 60uf not 100uf

 

[carbon]

Both of those look like standard run caps to me. You need one of the caps that @jo1010 put a link to. Or you may find that sealey can supply it as a spare part but is does need to be the start cap.

This is an example of a circuit breaker - its like a start capacitor but it performs like a switch?

70 uF capacitor with electronic circuit breaker | CEM

Optimise the operation of your single-phase motor with the 70 uF capacitor and electronic circuit breaker. Learn more about CEM!

www.cem-elettromeccanica.com

That was the first link I found as well

 

[Turbo]

This is an example of a circuit breaker - its like a start capacitor but it performs like a switch?

70 uF capacitor with electronic circuit breaker | CEM

Optimise the operation of your single-phase motor with the 70 uF capacitor and electronic circuit breaker. Learn more about CEM!

www.cem-elettromeccanica.com

You can also do the same thing with a standard capacitor and a small timer controlled relay.

The initial cost will be slightly more but when the capacitor goes wrong next time you just have to fit a standard capacitor.