Electric motor problem

I have a small drilling machine driven by a 1/4 HP induction moto

(British) sometimes it fails to start and just hums, if I switch of and try again normally it runs. This happens not on a regular basis sometimes it goes for days OK then plays up. Is there some sort o maintenance needed? Davi

-- stereotyp

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stereotype
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What tune does it hum ?

Reply to
John Stevenson

sounds like the start /run cap is on its way out. when its not working if you spin it up by hand does it run? new caps are quite cheap.

of course I could be wrong, no doubt someone more knowledgeable will be along shortly.

Dave

Reply to
dave sanderson

Check all the wiring for continuity and tight connections first, especially the leads that go into the motor terminals. They can sometimes work loose on older motors. As someone else said, after that, it's most likely the start capacitor, or it's wiring...

Chris

Reply to
ChrisQuayle

If it has a centrifugal starting switch (you can hear a click when it starts and again when it is nearly stopped) the switch contacts and the mechanism to operate it can be in need of cleaning. This usually requires disassembly of the motor. No lubrication is normally used.

Don Young, USA

Reply to
Don Young

Pretty sure it the cap that's getting old & 'leaky'. Hasn't failed altogether as it would never start or possibly blow mains fuse. They just get a bit worn out sometimes. Your cheapest and quickest option is to replace the cap, they don't cost much and are (normally) external so dead easy to get access to & replace. Tip - just be careful fiddling with any connections if you have recently attempted to start it, as the cap may hold a nasty residual charge which might make your hair stand on end, eyes light up and teeth rattle a bit!

Mike

Reply to
MikeH_QB

Anything, it doesn't know the words, so it has to hum.

Regards,

David P.

Reply to
David Powell

Thanks for all your input, yes Don it is a cetrifugal start motor, i'l take it apart and check the contacts. Davi

-- stereotyp

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Reply to
stereotype

I have this problem on two bits of kit I have just bought second hand. I can clearly hear that the centrifugal switch does not always 'click' back in when the motor stops so I assume that some lubrication is required. I'm planning on investigating further when I get some enthusiasm...

Reply to
eskimobob

I think cleaning is called for but I do not think that these mechanisms are generally lubricated. It might be ok in an enclosed motor where the dirt is kept out if no lubricant gets on the switch contacts.

Don Young, USA

Reply to
Don Young

Lubrication is normally the enemy of these switches as it harbours dirt. Complete cleanliness is normally the the best way IMHO

Bob

Reply to
Bob Minchin

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