How do I tell?

[Barnabas]

Sorry about this really simple question.

I had the electrics installed in my shed before thinking about welding and thus didn't specify anything special.
An armoured cable was taken from the fuse box about 5 metres away and feeds an ordinary 13 amp domestic socket in the shed. I have been running a 140A arc welder from it with no problems but only use short runs and haven't really put it to much of a test.

Having read all the advice on this excellent forum I have decided to buy a Portamig 181 from Weldequip (but he doesn't know this yet). I guess this can run at near max power off the domestic supply but would I be better off having a 16A socket? If so how do I tell what the existing wiring can cope with. It looks like a chunky bit of wire and the fuse wire holder has a yellow dot on it.

Finally - at what stage should you think about having 3 phase and what is involved to have it fitted?
Any advice appreciated.

 

[Ratty]

.... 3 phase and what is involved to have it fitted?
Any advice appreciated.

Vast expense usually, the leccy board will give you a quote. Make sure you're sitting down.

Sorry can't help on the other stuff but someone will

 

[irondarren]

3 phase is very expensive, Portamig do a 350amp unit that will run single phase, so we are talking about heavy fabrication here. Do you know what size the fuse is that feeds the garage? THe portamig will work better off a 16amp plug as you will be able to run it full power without the worry of a 13 amp fuse popping

 

[malcolm]

My 181 is still running off a 13 amp plug. I don't tend to weld thick things, though have run the welder on max power, but not for a long duration.

The cable to the shed will most likely be speced at way more than 13 amps. Depends on the wire diameter, though I'd be surprised if armoured cable is available in less than 30 amps. Should just be a case of putting a suitable trip/fuse in the consumer unit in the house and fitting another consumer unit in the shed to split the 16 amp supply from the 13 amp and the lighting. Parts would be less than £50, but you are supposed to get someone who knows what they are doing to install the electric bits and pieces which will most likely cost more.

Forget 3 phase. If it was cheap we'd all be running lovely TIGs bought from eBay.

 

[shenion]

Forget 3 phase. If it was cheap we'd all be running lovely TIGs bought from eBay.

Hehe, and have big drill presses, lathes,.......

Then again, used 3P equip would probably not be found so cheap

Been a real pain trying to get rid of my 3P welders.

 

[bs85]

A farmer i know got quoted £9000 for 3 phase and that was 6 years ago

 

[irondarren]

Nice if you can get 3 phase, then most of the big stuff that goes on Ebay and other auctions, is beyond the DIY brigade and often fetchs little more than scrap value

 

[Barnabas]

Thanks guys - that's helpful and puts 3p in context. WRT the fuse - I can't actually tell what it is apart from the fact that it is a yellow fuse holder whereas all the others are either red or white. Does that mean anything?

 

[irondarren]

Thanks guys - that's helpful and puts 3p in context. WRT the fuse - I can't actually tell what it is apart from the fact that it is a yellow fuse holder whereas all the others are either red or white. Does that mean anything?

I think it does mean something, red, white, blue and Yellow dots, i guess its a cartridge fuse which is rewireable?

 

[mart]

I think you`ll find that yellow is 20amp (white is 5, blue is 15, red is 30).

 

[bump]

IIRC, yellow is 30 amps.

It's been a long time since I last looked at a "fuse board"

 

[piman]

Helllo Barnabas,

the important thing is the size of the supply cable. The difficulty is accurately sizing it unless you work regularly with different sizes. Here's a link to some SWA cable data, which may help in identifying the size. Even so 1.5mm is rated over 20 amps in air. :- http://docs-europe.electrocomponents.com/webdocs/068f/0900766b8068f9d4.pdf

As a matter of interest three phase costs basically depend on length of run and the power rating you want. We asked for a quote at our place 12 months ago, the overhead cables run over our building so couldn't be nearer. The quote was about £8,000 as the board had to uprate the supply transformer.

Alec

 

[Barnabas]

Thanks for all those really helpful replies. I am glad that it's not such a clearcut and easy problem for a non- electrician but I feel that I'm a bit more knowledgeable about it now.

Have put in my order for the Portamig - very excited! and having had some reassurance from Steve will stick with the existing 13A setup and see how it goes.