i need help quick...

[agri-fabs]

i have a pickhill bantam oil cooled welder 180amp, all was going well with it until the other day, i was welding away and all of the light etc in the workshop dimmed and flickered, then the fuse blew,

whenever i try and plug the set in all the lights dim and keeps throwing the fuse (old fuse wire type)

so i thought it must be contaminated oil, so today i rushed out and bought transformer oil (£32 for 20litre drum in geartrodes) and i also bought some panel mounted femal dinze conectors,

whilst the lid was off the welder i fitted the dinze type sockets because they are much easier and last alot longer than the brass threaded bolts,

changed the oil (dirty colour came out and nice clear put back in,

put it all back together with new gasket etc,

plugged it in and the same happened again, dimmed lights then blew fuse,

i.ve tried the wiring and all that is ok, tried it in a different socket and done the same,

any ideas?

this is my only production set i have because i swear its just fantastic,


has anyone got a manual or anything for this welder?

or any ideas what could be wrong with it?

kind regards

chris

 

[Luke]

Have you got a multimeter? It sounds like its shorted, either across the transformer, or to earth, depending on how your supply is protected.

If you've got an RCCB, I'd guess at the transformer shorting, as the RCCB should trip on an earth fault before the lights dim.

 

[dai]

did you ask the lads in geartrodes,they are useally quite helpfull

 

[agri-fabs]

no i didnt ask the blokes in geartrodes because i thought the new oil would have sorted it!

luke, how would i go about testing it? i have a tidy fluke multimeter up the farm,

 

[Luke]

The easiest test would be for a short to earth, set the meter to measure continuity (sometimes marked 'diode test') and see if there's continuity between the Live and Earth pins on the plug.

Testing for a short across the windings isn't so easy, as there'll be continuity across the windings on a healthy transformer too.

I don't have any experience with the welder in question, but if I was in the same position, I'd look at disconnecting the transfromer from the supply inside the welder, and seeing if it still tripped. I guess on an old oil filled Pickhill that's a nuts and bolts job?

 

[piman]

Hello Chris,

the most vulnerable part is the supply cable, so I would check that for damage, then the cable connections.
A multimeter isn't the best instrument to check for an earth fault, but if that's all you have set it to a high range.
I wouldn't expect a short across the transformer windings, and as you have opened it up the winding connections must be OK?

Alec

 

[agri-fabs]

hi all, i have checked the inards of the welding set for any burnt windings and theres nothing,
i have checked continuity (beep test) between both 0volts and 240volt and 415volts againt the 'centre' earth and there is nothing,

i have visualy checked everything inside for anything touching eachother and theres nothing,

any ideas? please! or shal i just buy another one

 

[piman]

Hello Agri-fabs,

You should have a reading between 0 and 240, 0 and 415 and, 240 and 415. However open circuit would not blow the fuse.

Is this like an Oxford where the connections are on the lid? If so I would dismantle again and check the winding connections carefully. There should be insulating sleeves around the input connection studs, are they OK? These sort of machines are very basic so what the trouble is should be easily found?

Alec

 

[agri-fabs]

i've had a good look all through the input connections, what if i test between 0 and body of the machine? and also do the same with 240v and 415v

 

[agri-fabs]

i've had a good look all through the input connections, what if i test between 0 and body of the machine? and also do the same with 240v and 415v

just thought, that would be the same as doing it with the earth connection

 

[agri-fabs]

just thought, that would be the same as doing it with the earth connection

just been out and checked this, they are all insulated fine,

come on you lot, someone must know!!!

 

[piman]

Hello,

just re read your post, you should not get any reading between any of the 0, 240 and 415v terminals and earth. But what range was the meter set on, you say beep test, that sounds to be too low a range.

Alec

 

[agri-fabs]

i say beep test meaning 'continuity test' to see if currect could pass through or not,

i did not get any reading from doing the beep (continuity) test which tells me that it fine,

i have it rigged up to the crane now - out of the tank, all oil drined out and it still blows the fuse,

 

[piman]

Hello Agri fabs,

that is my point, the continuity test is not good enough. Really it needs to have an insulation resistance test done by a 'Megger' which (for 240v equipment) puts 500v across the insulation and measures the leakage current. A very low reading will show up with a multimeter if set to high range rather than just continuity, but it is not the definitive way to check.

Have you checked the cable for damage, inside the plug and inside the welder's terminal box.

Was there any sign of water in the oil when you did your first oil change?

Alec