Found Start Cap exploded!

[kengineering]

I was called to repair the table saw of a friend. I found the start cap had litteraly exploded in its cover plate. Just a roll of paper and plastic bits. He said the motor had been replaced 2 months ago and had worked fine until yesterday. Any ideas what can cause this? Ken

[afeef]

I was called to repair the table saw of a friend. I found the start cap had litteraly exploded in its cover plate. Just a roll of paper and plastic bits. He said the motor had been replaced 2 months ago and had worked fine until yesterday. Any ideas what can cause this? Ken

hi
there is 2 reasons i gess
1-the capasitor has factoty defects, bad materials or loos connections
2-the saw is jammed in some times , that increase the current passing thru starting coils , then blows the capasitor
recomondation:make the on-off mode as low as you can , cause every on-off strike the saw consume twise the rated current, and that affect the starting coils and capasitor and shortend there life
all the best
afeef

[Peter_1]

wrong wired ?

[kengineering]

I thought it was wired wrong myself but there were a few sets of cabinets cut since replacing the motor and it ran just fine. As far as being stuck I guess its possible but I am told it happened on start-up with no load on the saw. The defect theory may have some teeth. Ken

[chillin out]

Is it one of them old Brook Crompton motors?

There is a clutch thing at the back of the motor (inside) that switches start/run windings. Check this is ok.

Chillin

[jamcool]

check the centifugal switch it might be bad so on start up it stays shut and stays on start not opening to run

[Andy]

Hi
a capacitor will blow up the nicest you have ever seen if you apply voltage to it the wrong wall (older fixed polarity) or again any capacitor if you apply voltage the wrong way before it discharges.

Kind Regards. Andy

[kengineering]

How do I determine a bad centrifugal switch?
Thanks, Ken

[wambat]

How do I determine a bad centrifugal switch?
Thanks, Ken

Usually located back end of the motor. I
agree it's probably a defective switch, sometime all you may need is a little lubrication. You will have to remove the back cover on the motor

[chillin out]

How do I determine a bad centrifugal switch?
Thanks, Ken

Once you take it to pieces you will see if its ok straight away. Contact will be stuck together or blown apart.


Chillin

[kengineering]

I will check next week when I visit.
Thanks, Ken