Clarke 151en Turbo - help!

[RodAndTom]

Hi,

I was happily doing some pulse welding of a new sill on to my Mini and all of a sudden - wire won't feed through. Is it likely to be just the wire feed motor?

I can't tell if the ability to create a spark stopped or if the wire just stopped feeding. I know for sure that the wire isn't welded to the tip and there is no nasty spool of wire inside so the sleeve is good.

Am I looking at a completely dead unit - although the fan still spins:-) or just the wire feed motor?

Would the wire feed wheel turn with the trigger pressed? Is that a good test of whether the motor is stuffed or not?

Thanks,

Rod

 

[anjum]

Might just be the contacts in the torch.

 

[RogerTram]

Hello Rod your unit is very much like one I used to own. Firstly when you pull the trigger on your gun do you hear any clicks or a dull thump come from within the welder. On my unit I could hear the power relay switch over and the transformer energize even with the wire speed set to zero and arc open. If you do then expensive things might be ok in there. Next completely remove the contact tip from you gun and press the trigger some times a perfectly good looking tip can be too tight to feed if you have arced it over. I did it on the very first weld with my new welder with a brand new tip and had to change it.

Secondly take your torch apart and have a look at the little brass switch leaf behind the trigger make sure its still soldered to it's wire. Next wearing non conductive gloves with the machine turned on and the wire speed turned down low but not off briefly touch the leaf switch to the torch valve block to see if anything moves. If it does then its very likely that parts have moved in your torch while you pulsed it on and off. Just resemble your torch again with the parts in the right order which might me a little fiddly to get right without a diagram but am sure you will get it right after a couple of goes. But if nothing moves your next thing to check is the connection within the welder itself. Pull the mains plug out of the wall and take the transformer side of your welder off next follow the thin trigger wire which connects to the leaf switch out of the bottom of the torch hose to where it connects inside the unit and if you have a multimeter check the continuity of the wire from the torch leaf to where it connects in the welder if it reads zero replace the wire.

Now if that's not fixed it if you have a soldering iron remove the wires on the back of the wire feed motor make sure you label which one connects to the motor terminal marked with a ringed + mark or red paint spot on the back of the motor. Next using a 12v DC supply connect it across the motor terminals for a second or two. If the motor does not spin up then its duff. Its a common RS-540 24v short shaft DC motor. You can also buy complete wire feed units as a replacement.

Have a look at the PCB if you can see the back of it and pay attention to the solder pads at the back of the relay packs they are the large plastic cased blocks on the component face of the board. Have a look to see if the solder as cracked causing a dry joint to one of the the relay packs. If you don't see anything and your handy with a soldering iron then it wont hurt to re flow the solder pads of all the components on the board with a dab of flux cored solder.

Another thing that could have gone is a small fuse on the PCB replace it with the correct rated fuse. if it blows again the PCB is in need of replacement. And finally it could be one of the thermal protection switches on the diode pack (square Alu thing with black round things on directly infront of the fan) or on the transformer. The switches themselves look like round black objects with two spade connectors on the back. just pull off the connectors and check across their connectors with a multimeter they should read conductive when cold. If not you have a duff one but make sure you got the right temperature you will find it marked on it some where around the side of the plastic part or if not stamped into the metal face.