Help identifying TIG welder problem

[cheekychimpo]

My first post guys so Hi to all.

I was hoping someone may be able to give me a few pointers on a problem thats occured today.

I was trying to tack an old spanner up for a little project, switched the tig on, it began to drone,I touched the switch on the torch and the fuse blew.

I replaced the fuse tried again, same thing happened.

The tig is a old piece of kit, its a Migatronic LTE140 DC only unit,on top left of case it says LEHF.
Running it on single phase(although its switchable to 3phase)

Anyone have any ideas? Ive only been using it a couple of days.

Thanks Paul.

 

[MrFluffy]

I sort of have a variant of that on my boc adr tig. If Im welding heavy thicknesses, and the torch doesnt quite take up properly (ie a bit of switch bounce) then when it bounces it pops two of the breakers out (its 3 phase) with the voltage surge it causes.
I either tap the tig torch button on something before striking up the arc to try and avoid any switch bounce, and sometimes I have to drop the current a little bit before establishing the arc proper.
Im pretty sure in my case its because Im operating it at the limits of what my supply and consumer unit can handle coupled with a dodgy button on the tig torch itself, maybe its asking for a bit more current than the fuse can handle for you too? Could be worth firing it up on very low amperage and seeing if it pops the fuse...

 

[cheekychimpo]

Ive tried on low amps,same problem MrFluffy.
The set used to be silent when I turned it on, then began to drone when the arc kicked in.

Now the set makes the same noise when started up(no arc) as what it used to be under load?(actually welding)

Then as soon as I hit the switch...pop, fuse blown.
Also the fan kicks in even when its not welding, as if its under some sort of load?

Hopefully you can understand my jibber-jabber, Im no expert.

 

[shenion]

Sounds like the diode bridge went or a short in the transformer. Could be expensive fix.

 

[cheekychimpo]

Shenion, does the transformer resemble a large coil? (loads of thin plates surrounded by thick wire)
Ive taken the cover off and had a look inside for any obvious problems and spotted two of the items mentioned above.

 

[shenion]

Yes, usually there are 2 large ones and a small control transformer.

Is this the fuse on the outlet or one on the machine?

 

[cheekychimpo]

"Is this the fuse on the outlet or one on the machine?"

Do you mean where is it fusing out?
The set has built in fuses, they are all ok, the fuse in the plug(240v) is popping.

Thinking about what you said earlier, a short in one of the transformers sounds viable,its as though the machine is welding even when it isnt, then when I do actually start to weld the whole thing overloads and pops the fuse.

 

[cheekychimpo]

Well guys I called in my local welding supplys place and asked them for advice, they offered to check it over for free.

I explained the symptoms and they said similar to shenion, it sounds like a trans is shorting.

I asked how much to get it repaired and he said "forget it"
So what do you guys suggest, do you know if its viable to repair?
Where could I get it repaired if possible?
Are replacements available on such an old model?

Any advice would be great.

Thanks Paul.

 

[whycanismellburning]

who did you call in stoke?

 

[cheekychimpo]

I called in the welding place across from Focus DIY in cobridge, Ive spoken to them before about shielding gas, they seem helpful guys.

 

[whycanismellburning]

I'm down in tamworth but i go to GTA in Walsall and they always seem be the best on price... might be worth a call!