Help needed with transformer and switch wiring.

[Dave1324]

Right guys, the other day i picked up an old welder, its made by a company called awelco and its a standard power 185, also sold as a kamanchi platinum 185. i bought it as a non working unit and it looks like ther guy has had a go at fixing it but some of the wires from the transformer to the switch were loose inside, ive found the original problem to be either the small relay on the low voltage side or the thermal switch (not allowing the relay to close) so ive sorted that problem temporarily by manually closing the contacts on the relay and everything works as it should now but as soon as you pull the trigger on the gun it trips the electric, which i assume is because the switch is wired up wrong because when i hook up the primary winding to the contactor essientially bypassing the switch it welds fine but is stuck on its lowest setting because you cant operate the switch. Now theres 8 settings on the welder and 8 wires coming from transformer, the longer one goes to the neutral on the contactor then the other 7 go into the switch and there should be a live coming from the contactor to the switch but this wire was loose and i cant figure out where it should go on the switch, the switch is numbered 1, 2, 3, 4, 5, 9, 10 there some un numbered contacts on the switch but have jumpers on them, numbers 5 and 10 also have jumpers connecting them to 2 other terminals, i am completely baffled as to how this switch works or how to even test it with a multimeter so was hoping that someone on here could give me a bit of advise or better yet if anyone has one of these welders if you could show me what goes where?

Cheers, Dave.

 

[mike 109444]

Welcome Dave.
Are you sure it has 8 power settings as I can't see you have enough wires (one short!) Could it be it has 7 and an off position ? see pic

 

[Dave1324]

Welcome Dave.
Are you sure it has 8 power settings as I can't see you have enough wires (one short!) Could it be it has 7 and an off position ? see pic

Yes it has 1-8 on the selector panel, the welder is identical to the one on this post http://www.mig-welding.co.uk/forum/threads/kamanchi-185.27045/

Thanks for the diagram but im not certain the transformer works like that as only 2 or 3 wires coming from the transformer have continuity with the wire going to the neutral unless im overlooking something. the transformer also looks in great shape, no charred wires or any signs of it getting too hot. i have emailed awelco directly and the uk distributor to try and track down a wiring diagram but im not holding my breath.

 

[mike 109444]

Well as the neutral should be common and there for you should get a reading on ohms setting from the neutral to all of the tappings unless there is a break in the winding. If you look at the pic and say connect meter to neutral then other meter probe to 7, 6 , 5 and get a reading but then nowt from 4, 3, 2,1 then that would match what you have found. Do the wires that come out of the transformer to the switch form a loop as the end (so there is two bits of wire in the sleeve) or is the wire at end of sleeve two ends ? (one sleeve may only have one wire)

 

[mike 109444]

This is what I was trying to explain in the above post !
This sketch would be a 4 power setting mc BTW

 

[mike 109444]

Dave you might find this post a good read esp the video in post 48
http://www.mig-welding.co.uk/forum/threads/siegen-180-so817-wiring.54517/page-3

 

[Dave1324]

Well as the neutral should be common and there for you should get a reading on ohms setting from the neutral to all of the tappings unless there is a break in the winding. If you look at the pic and say connect meter to neutral then other meter probe to 7, 6 , 5 and get a reading but then nowt from 4, 3, 2,1 then that would match what you have found. Do the wires that come out of the transformer to the switch form a loop as the end (so there is two bits of wire in the sleeve) or is the wire at end of sleeve two ends ? (one sleeve may only have one wire)

no each wire coming from the transformer has a single wire in each sleeve, ill try and get some pics and make a diagram of everything tomorrow. Cheers

 

[Dave1324]

Dave you might find this post a good read esp the video in post 48
http://www.mig-welding.co.uk/forum/threads/siegen-180-so817-wiring.54517/page-3

cheers mike, that video was very helpful. im going to have another crack at it tomorrow.

 

[Dave1324]

heres some pics of what im working with.

 

[mike 109444]

Not sure how you can get 8 power settings from a transformer with 7 + 1(common). Is it possible that there is a broken off wire on the transformer or a wire coming out of another part of it ? (having in mine that it has been "had a go at fixing" by previous owner)
The pics attached are of a transformer I rewound (I did not fry it!)
It had 6 power setting and could be jumpered for 220 or 240 input So there are 6 + 1 (220) + 1 (240) connections = 8 wires in total. The 240 wire you might refer to as a common.
I ended up rewinding and added more tappings to give 11 settings.
As you have worked out how to by pass the switch for 1 power setting it would pay to go through each of the taps connecting one at at time and noting the voltage at the output then mark up each one so you know which one is which. Label with tape!
Think you have to view/think of the switch as a stack of three separate switches which have been joined together mechanically AND by the link strips, electrically So when power 1 or 2 is selected the first slice of the switch is used then on 3 or 4 the second slice and it gets it's common via the link strip and so on. Hope that makes sense.

 

[Dave1324]

thanks for your help mike, i had received an email back from awelco this morning telling me that this welder is not one of their products so i sent a few photos back and after a little while of searching ive found an instruction manual for the kamanchi 185 welder and it just so happens to have a circuit diagram https://www.yumpu.com/it/document/view/35114686/untitled-kgk-a-s/3 on page 30, from what i can make out there is 4 windings on the transformer and when switched between 1 and 4 its selects a single winding then positions 5-8 it starts combining windings to give the other 4 settings? im going to give it a whirl tomorrow.

 

[mike 109444]

Odd way but at least you have the diagram now