Looks to be the solution move from 400v connection to 240v connection.

If in doubt ring them up and they will advise.

Looks much the same as my old OXFORD welder which in addition had an 80V tapping for single carbon brazing (a bit old hat now).
BobH

Hi Rainbows

Re Dave Daniel's comment regarding the possibility of the transformer oil containing PCBs. The label in your photograph of the control switch states, in very small print, that the transformer should be filled with Shell Diala B Oil. A quick search found this data sheet which states that Diala B contains NO PCBs so if they stuck with that then there should be no problem, one hopes.

Martin

it looks very muck like the old oxford set that i have, and yes the live is on the 240 pin, i have mine on a 16A blue plug, and in domestic settings off the cooker circuit, but i have run 6mm rods all day welding 1/2" plate to the hull of a boat with no issues, much prefure the oil filled ark welders, i find them much smoother on start up, and in general

i always plug stuff like heavy welders or trasformers into the cooker circuit, normally just through the plug that is next to the switch, because a normal household circuit is only 16A but the cooker is normally 30 or 32A so will take the initial surge better, i now have a dedicated 45A breaker in the garage that i run big stuff off which works well, and with the 16A blue plugs not having a fuse helps, even if its not best practice, it should really be on a 32A plug but that would mean just having a dedicated plug just for the welder and i dont use the stick ark that often any more at home, its mainly only used on heavy stuff on site

I too had one, in fact I once went for a job at Pickhill, didn't get it tho'. I had it wired thru' the cooker circuit using old round pin plug ,no fuse. BTW sold the cooker first and bought a gas one so no extra load on circuit. Ran 4mm rods no bother, also easier to use on thin rods than the smaller diy welders. Still using the circuit but with a more modern fan-cooled welder ( easier to move about ).

Please don't. What I have done, and this is most likely not approved- Wire in a fused spur, wire in a 3 pin socket after that and fit a round 3 pin plug to the welder. Fit a 20 amp fuse to the spur. I used a cooker socket which has a standard square pin plug socket also, comes in useful. If the welder comes with a industrial type round plug then fit the socket after the fused spur.

It's a single phase transformer, regardless of the voltage you connect it too – there is only one primary winding with several voltage taps. If you have 3-phase, you'd connect across any 2 phases (415V) – this is better than connecting from one phase to neutral (230V) as the current is lower.

One issue that comes up with large transformers is the tendency to saturate periodically at turn-on. Despite what people assume, there isn't an inherent surge current when connecting a transformer, as it's just an inductive load. However, you will find that when disconnected, there can be some remaining magnetisation of the cores ("remanance&quot which depends on exactly when in the cycle the mains is removed. If you then reapply the mains at the right (wrong?) instant, the cores can be driven to saturation due to additive magnetisation. The only cure is to fit a soft start which could be as simple as a timer and a resistor. A slow (type C) MCB may help – but usually not.

Murray

Unlikely to make any significant difference. If the welder is rated at something like 30A on the primary, the winding resistance will be a small fraction of an Ohm.

I'd estimate about 0.5 Ohm for a 15m long 13A extension cable (30m return length), so hundreds of amps current fault current on a good day.

As for the voltage drop would you expect across the extension with 13A flowing – probably about 6.5A on that basis ie 85W dissipation in the cable which feels about right – and why it's not a good idea to run it coiled up as you noted.

I did some testing on my large Interlas TIG welder some years ago when figuring out how to prevent nuisance tripping when I switched it on. I fitted a delay timer / resistor soft start circuit controlled by the start switch. The resistance has to be large enough to limit the saturation current but low enough to be able to generate something close to the normal magnetisation current. In practice, that results in a value of a few Ohms which is more than you could tolerate under any load. Typical cable resistances aren't in the right range.

Best solution is to use a proper phase control soft starter but these cost serious money.

Edited By Muzzer on 05/04/2016 22:50:43

That little fusebox looks like an outlet for a fixed appliance ie: a cable would come out of that round hole straight to the appliance. The appliance would then have its own fuse sitting in that box. The circuit looks like a ring main and doesn't need a fuse in that box. Unfortunately, that fuse box has a fuse limit of 13 amps, so you could not wire your welder into it and put a 20 amp fuse in the box as it would not fit.

BobH