Faulty Compressor

[Philly]

Hi, I recently got my hands on a faulty compressor. It will start up for a couple of seconds then the safety switch will cut in and turn it off. So I whizzed the motor off, stripped it down and cleaned it. I greased the bearing as it was a little stiff(was used in a factory with flour, it was everywhere). Then when it still didnt work I removed the safety switch and tested again. It fired up and will run and compress air as it should, but after around 30 seconds the remaining flour/string on the motor coils starts melting and it starts smoking.

What could be the cause, could it just be the coils are knackered, meaning it will need a new motor? Does the motor need any form of lubrication?

Last of all, if I can get a motor are they generally unversally fitting? Its a SIP 2hp 50ltr. It will only be used for general household dutys

Cheers

 

[piman]

Hello Philly,

yes sounds like a new motor. If you take off the terminal cover and smell a burnt sort of smell, it's had it.

Motors have frame sizes stamped on the label and I'd expect that it's a fairly standard one (2H.P. =1.5KW). Just make a note of the speed also as you'll need to match that.

Alec

 

[Philly]

Cheers Alec, any ideas of where to grab a new motor? If could it be worth buying a cheaper new model from ebay and using this as an extra reciever?

Cheers, Philly

 

[rtbcomp]

I've had a motor off these people :

http://shop.ebay.co.uk/goldcresttechnologies/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686

You need to check mounting hole layout, power, voltage, shaft diameter and key size.

The motor should also be capable of being set up to rotate in the right direction.

If the motor doesn't have a built-in cutout then it would be as well to get a proper direct-on starter with built-in overload protection.

 

[Philly]

http://cgi.ebay.co.uk/Electric-Moto.../350385567362?pt=UK_Air_Tools_and_Compressors

Seems like a fair price, I will look into all the details as Im not sure what the key size etc is Is it like to say on the machine or is it a case of finding a manual?

Thanks

 

[piman]

HelloPhilly,

the frame size covers mounting bolt pitch, shaft height, shaft and keyway size, so that's all you need.
An alternative source is Machinemart.

Alec

 

[Endacy]

I too bought a motor off of Goldcresttechnologies via ebay. I was very pleased, it was well packed and works fine - it's on a radial drill.

 

[Philly]

Right, I checked the manual and it didnt mention the frame size. Guess I'll have to get the tapemeasure out.

Would there be any issues with sticking a 3hp motor on there rather than the 2hp, because I would mind touching up some panels on my car

 

[rtbcomp]

It'll still run at the same speed so you won't get any more cfm, although it should achieve a higher pressure before the motor starts to labour (watch the tank rating though!).

If you want more cfm you will have to increase the motor pulley or decrease the pump pulley slightly as well as fitting a more powerful motor.

A bigger motor with the existing pullies will be less stressed though.

If the motor you have runs at 1400 rpm don't be tempted to increase to 2800, it's too big a jump.

 

[Philly]

Cheers for the info Does it make any difference that its direct drive? I probably should have mentioned that earlier.

 

[rtbcomp]

Ah, yes it does! You're stuck with the gearing, get a motor the same size, you won't gain by fitting a bigger one.

Does the motor still have a plain shaft with a woodruff key like the Ebay/Machine Mart ones?

 

[Philly]

I'll have to check, Im not entirely sure what the woodruff key is, but being a SIP Im guessing so. What do I need to look out for?

 

[rtbcomp]

I'll have to check, Im not entirely sure what the woodruff key is, but being a SIP Im guessing so. What do I need to look out for?

http://en.wikipedia.org/wiki/Key_(engineering)

 

[shenion]

Many direct drive compressors, the motor is not replaceable.

 

[piman]

Hello Philly,

not the manual, look on the motor nameplate, there's usually a section called frame.

Alec