Clarke 100en - adjusting the potentiometer?

[Fe2O3]

Hi there,

Just purchased a 100en on eBay. Everything functions well......except one thing; the wire feed is ~8m per minute regardless of the speed setting - zero to ten, it just shoots out.

On another thread, somebody mentioned that the potentiometer can be adjusted, but they didn't mention how.

I'd appreciate advice as I don't really want to part with ~£60 for a new PCB.

Thanks.

 

[rtbcomp]

Welcome to the forum

You can get the manual from here

http://www.clarkeservice.co.uk/product_manuals/mig_welders.shtml

The circuit diagram is on page 30.

The only potentiometer I can see is the actual speed control which is in series with the motor.

Some welders have a transistor circuit which incorporates a trimmer pot. to set the speed range, but the 100en would appear not to have this arrangement.

I would have a close look around the pcb and speed control for a short circuit, (loose piece of welding wire for example) if all seems OK check the speed control pot itself, it may have shorted internally.