LGB Track cleaner possibly shorting

[Airbuspilot]

We have the LGB track cleaner which was working perfectly but needed replacement cleaning wheels. I replaced them yesterday and ran the loco everything works as expected but when I select the cleaning motor it seems to short circuit and dies on me. After a few seconds with cleaning motor OFF it resumes normal working, forward, back, lights etc. selecting cleaning motor with speed selected to zero warning lights on roof flash but when speed increased from zero it again seems to short circuit.

I have removed the motor block again and there are no cables touching but when I opened the motor block there is what looks like a capacitor of some kind inside. I assume this is a capacitor but there are no normal capacitor markings showing its value and its in series with the motor which doesn't make sense. Does anyone know what it is and what it does?

As all connections are clear of each other and wires in good condition I don't see anything which could cause this problem, the cleaner worked correctly the day before with its old wheels.

Robin

 

[Gizzy]

Capacitor is probably a suppressor to eliminate noise picked up by Television.

You could check to see if it has shorted by removing on wire, but I think it's unlikely.

Double check everything else....

 

[PhilP]

If the 'capacitor' is in series, it is probably a Polyswitch thermal fuse..

Did you clear any strings of plastic from around the cleaning wheel axles?

A Polyswitch will be HOT if it has operated, so you can check, but be careful!

The cleaning motors get a lot of abuse and filth, so can fail.

PhilP

 

[mike]

It is actually a thermal switch.
When the motor gets too hot( due to wear, load) it trips and the on bord electronics are protected.

 

[Airbuspilot]

It is actually a thermal switch.
When the motor gets too hot( due to wear, load) it trips and the on bord electronics are protected.

Thanks, that makes sense hence why it is in tight to the motor. Presumably if this is activated it would simply stop the motor operation not look like a short.

I have removed the cabin and motor block but there are no wires which look to be touching, i will have another run this afternoon.

Robin