My almost new benchtop sander (as above) stopped working because the (push on push off) switch failed. This was replaced and the machine worked well for a few hours, then smelled of smoke/hot electronics. I investigated and found the capacitor very hot and with a small blow-hole in the top. I changed the capacitor with an exact replacement from the maker. Switched on and within moments the same nasty smell of hot electronics happened again. The capacitor was VERY hot.
Any ideas, please, as to what's wrong and how should I proceed to get my useful sander back in full action?

 

Are we to guess what brand and model of sander you have?

 

Apologies, it's a FERREX branded version of a Scheppach.

 

Apologies, it's a FERREX branded version of a Scheppach.

That clears every thing up, thank you.

 

Sorry, am I missing something? Would a photo of the manufacturer's plate - on the machine - help? Sorry if I'm being thick.

 

Let's see now. Googling "Ferrex" gets hits for a iron pill medicine. Scheppach gets many many pages of wood working tools. So if someone asked you to try and help with the information you gave the forum, could you? Personally my crystal ball is in the shop getting recalibrated this week.

 

Is it a start or run capacitor?
Maybe it's just for starting the motor and not disconnecting

 

A couple of thing it could be, No1: is it a AC motor rated start/run capacitor?
N02: If it is a correct start capacitor the method used to switch it out of circuit could have failed. As previous post #7..
More details on the motor is needed.
Max.

 

Is it a start or run capacitor?
Maybe it's just for starting the motor and not disconnecting

Is it a start or run capacitor?
Maybe it's just for starting the motor and not disconnecting

Thank you very much Rich2 and Max. TBH I'm not sure whether the capacitor is a start or run or both - version. I do know, however, that the new capacitor is correct since it's exactly the same as the original one that I took out of the machine.

I have a horrible idea that what you've both said is correct, in that it's a start capacitor which doesn't get disengaged after fulfilling its function! There is what looks like a solenoid linked into the wiring loom, which would presumably be the device which is meant to trigger the capacitor for starting purposes and then is meant to disengage. I wonder if Scheppach would kindly send me a new solenoid? It's supposed to have a three year guarantee, and only bought in January of this year!

So, thank you once again.

Dave R.

 

There are typically two types of start switch, a centrifugal one on the motor shaft, the second is external and consists of a current sense relay which opens once the start current has decreased.
If a start capacitor remains in circuit it is usually destroyed.
Max.

 

. TBH I'm not sure whether the capacitor is a start or run or both - version. I do know, however, that the new capacitor is correct since it's exactly the same as the original one that I took out of the machine.

All of this could have been avoided by giving the model number of the machine like you were asked earlier. A brand/maker is nice but ti also needs a model number or name, so the manual can be looked for. If it failed that fast when new, and was replaced with the same type, the original one was the wrong type or value. Most manuals will have a parts breakdown and the cap could be compared to that.