Workshop wiring?

[Debs.]

I already have a barn-workshop with a 32A MCB protected spur (6 mm. T & E) from the consumer unit in the house feeding 'several' 13 & 16 Amp. wall-outlets wired-together as a workshop 'ring'.
Running off that; there`s a large fridge/freezer, drill press, compressor, arc-welder, flourescent-lighting, grinder/cut-off saw and many 'portable' wood/metal working power-tools.

I understand the 'diversity' aspects of electrical power use.....but if I get a large MIG (as I hope-to in the next week or two) should I consider a (new) single 'dedicated spur' serving an isolator/contactor with a 16 and a 32 Amp. socket, just to run the 2 welders.

The house` consumer unit isn`t too far`as a cable run from the barn/workshop and I have to-hand a spare consumer-unit bay, a 32 Amp. MCB and a drum of 10mm. T & E ('old colours'; but who`s to know out-here in the 'styx').....so, aside from having to drill a hole through a 3 ft. thick loose-stone wall; the job would be easy and cheap to do.

A good idea perhaps?......What do you all think?
Kind regards,
Debs.

 

[Wozzaaah]

When you say large mig, what sort of 'large', my 360A mig 'requires' a 45A supply but I run it off a lot less than that. I don't imagine you're planning on buying one that big so you might get away with what you have now as long as you don't need to run the mig at full power. If it's just you working in there then you won't be running both welders simultaneously but if you do then you will definitely have to up your supply.
Also, a big welder is better run off a C or D rated mcb, C being motor rated and D being resistive/inductive load (I think). They trip at different levels of their maximum load to cope with the rush of current at startup.
To be honest, if the cable run isn't too long it wouldn't cost you much to run a new submain to the workshop using armoured cable rather than t&e. If you do use t&e, I'm not sure the earth conductor would be big enough. A submain would make it more expandable for the future.

 

[Debs.]

When you say large mig, what sort of 'large'... mig....

I`ve been a lucky lady: I`m being 'gifted' a Sealey PowerMig 2500 (several years old, but good-condition) which IIRC is a 250 Amp.`set.....finger`s crossed to be collecting it next week.....I`m itching to get-started and practice with it.

 

[Wozzaaah]

Nice gift!
If it's quite old then you may find it needs a bigger supply than a newer one would, you won't know until you get it really. The data plate on the back might be useful to you, it should tell you quite a bit about it.
One of the first things to do when you get it is give it a good clean inside and out, blowing all the crud out from inside and also give the torch a service, replace the liner with a new steel one and put a new tip and shroud on.
If the newer 2500 is the same innards as yours then it specifies 6.6kva which equates to 28.7A at full power so just within your 32A supply as long as you don't run anything else at the same time. The worst that can happen is the MCB will pop so not really too much of a problem.