Pillar drill 'Humming'.

[ellal]

I have a pillar drill which has been working fine, but just came to use it and when turned on the chuck moves a fraction and there is a 'humming' sound before it clicks off.

I can turn the chuck by hand and checked for any problems with the belts, but the cogs turn ok.

By process of elimination it sounds like it might be an electrical problem so any ideas as to how I could diagnose further would be appreciated.

 

[ricicle]

If it is a single phase motor and the windings have not burned out then the capacitor (if fitted) could be goosed.
If three phase then check the supply and control for phase loss.

 

[ellal]

It is a 500w single phase DIY machine. This is the model

So I assume if it is the windings then it is an uneconomic repair?

how and where do I find out whether it has a cap and how to tell if it has failed?

 

[bernardgreen]

The capacitor is in the cylindrical "power bulge" at the back of the motor.

 

[ellal]

I'll just go and check!

 

[ellal]

Ok, this I what I found.

View media item 74979
How do I tell if it has failed?

 

[Norcon]

You can check it with a multimeter. The two wires will probably terminate in the connection housing.

http://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html

 

[Spark123]

For the price of a new capacitor it is worth a shot at replacing it, a multimeter measurement won't be that accurate if it is breaking down under voltage.

 

[Norcon]

If you disconnect the pulleys and spin the motor by hand as you press the switch and it starts then its definitely the capacitor.

If your not happy with your hand on the pulley then wrap a cord around the pulley and give it a good pull and then hit the switch.

 

[conny]

If you disconnect the pulleys and spin the motor by hand as you press the switch and it starts then its definitely the capacitor.

If your not happy with your hand on the pulley then wrap a cord around the pulley and give it a good pull and then hit the switch.

DO NOT DO EITHER OF THESE!!!

If you don't get your hand out of the way or the cord does not come clear you are in danger of losing a couple of fingers!

Just make a note of the capacitor details and buy a new one from an electrical who;esalers such as CEF or Denmans. They cost less than a fiver. If they haven't got one they will be able to source you one. The capacitor is 99% certain to be the fault.

Norcon, next time someone asks how to check for voltage are you going to tell them to lick their fingers and touch the cables?
The prime aim of this site is to teach diy'ers how to do something correctly and SAFELY!

 

[winston1]

You can check it with a multimeter. The two wires will probably terminate in the connection housing.

http://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html[/QUOTE]

What a load of crap that is. Can't believe someone would suggest putting a capacitor across the maid and then shorting it. The result would depend on which part of the mains cycle you disconnected it.

None of the 4 methods would determine the value.

 

[JohnW2]

What a load of crap that is. Can't believe someone would suggest putting a capacitor across the maid and then shorting it. The result would depend on which part of the mains cycle you disconnected it.

I agree - and not just crap, but dangerous, for all sorts of reasons.

None of the 4 methods would determine the value.

The first three certainly wouldn't - but don't even claim to. The fourth method (use the capacitance range of a meter) will obviously give an indication of the capacitance within the accuracy of the meter, provided it is within the range that the meter can measure. I've actually been quite surprised and impressed by how accurate the capacitance ranges of even very cheap multimeters can be, certainly for small-medium capacitances.

Kind Regards, John

 

[ericmark]

You can check it with a multimeter. The two wires will probably terminate in the connection housing.

http://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html[/QUOTE]

What a load of crap that is. Can't believe someone would suggest putting a capacitor across the maid and then shorting it. The result would depend on which part of the mains cycle you disconnected it.

None of the 4 methods would determine the value.

I would agree it's as bad as the bit of sting on the pulley. Seem to remember one of my meters needed a 10 volt AC transformer to measure a capacitance and meter went in series but never tried it.

With burnt out start winding or fault capacitor flicking pulley would likely start the motor so the flick the pulley method is not only dangerous it is also useless to tell it rewind or capacitor required.

When looking for a replacement motor for a compressor found cheaper to buy new compressor since you will need to take to rewind shop even if buying new motor to swap the pulley to get it for less than £61.86 is going to be hard.

 

[Norcon]

If you disconnect the pulleys and spin the motor by hand as you press the switch and it starts then its definitely the capacitor.

If your not happy with your hand on the pulley then wrap a cord around the pulley and give it a good pull and then hit the switch.

DO NOT DO EITHER OF THESE!!!

If you don't get your hand out of the way or the cord does not come clear you are in danger of losing a couple of fingers!

Just make a note of the capacitor details and buy a new one from an electrical who;esalers such as CEF or Denmans. They cost less than a fiver. If they haven't got one they will be able to source you one. The capacitor is 99% certain to be the fault.

Norcon, next time someone asks how to check for voltage are you going to tell them to lick their fingers and touch the cables?
The prime aim of this site is to teach diy'ers how to do something correctly and SAFELY!

Its safe. Have done it a few times. And no more dangerous than starting a Honda engine.

 

[Norcon]

You can check it with a multimeter. The two wires will probably terminate in the connection housing.

http://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html[/QUOTE]

What a load of crap that is. Can't believe someone would suggest putting a capacitor across the maid and then shorting it. The result would depend on which part of the mains cycle you disconnected it.

None of the 4 methods would determine the value.

Then what method would?
Fitting a new one?