advice-Installing 32 amp socket in garage.

[projectwelder]

I have read through many threads online and including threads on this forum, but I'm still left considering options for my property.

I have just bought a highier power single phase 250amp mig welder and I want to be able to use it to it's full potential.

I would like to fit a blue 32 amp comando socket for the welder in my garage.

I do have power in the garage supplied off my house mains.

The garage power is taken of the sockets curcuit ( 16 amp breaker ) from the house in 2.5 twin and earth cable to a small consumer unit in the garage that powers a few florescent tube lights and few double sockets.

My mains fuse box is full, so I can't add another dedicated breaker in there.

What I am wondering though is as the shower is 40amp breaker and what looks like 10mm twin and earth cable, can I spur off that to another seperate new consumer unit in the garage with seperate breaker type c for the welder, then to a isolator switch and finally to the 32 amp commando socket?

Any new cabling would not need to run underground.

I've tried to explain the situation best as posible as I know it can be confusing without seeing the system thats in place.

As usual, I would like to do the work myself to keep electrician costs to a minimum.

Some pics of the main house fuse box and the small consumer unit in the garage.

Thanks.

 

[brightspark]

in short no u cant spur of the shower cable as that must have its own dedecated supply and if the garage consumer unit is fed from a 16 amp breaker and wired in 2.5mm cable its pointless having the 30 amp- breaker in your 2 way unit as your limited to `16 -amp at source. minimum cable size for 30 amp would be 4.0mm

 

[projectwelder]

Is that to do with the regulations then?
Is my only option to get a new mains consumer unit with space for a dedicated 32amp Ctype breaker?
I read 6mm t&e cable is enough then isolator then the socket.
What would be a cost effective way to go about this?

Thanks for reply.

 

[puffernutter]

Agreed. If you disconnect the shower and dedicate that feed to the garage it would be OK (but probably unpopular). You would also need with 6mm or 10mm FTE dependent on the length of run to the garage and the voltage drop (if you want the welder to run at full capacity).

Here's a really daft suggestion - could you have a 40A changeover switch (shower/welder?)

Cheers

Peter

 

[projectwelder]

I too have be wondering if this would be viable. Obviously the shower could now not be used while the welder was in use. But might be a viable option?

 

[brightspark]

Agreed. If you disconnect the shower and dedicate that feed to the garage it would be OK (but probably unpopular). You would also need with 6mm or 10mm FTE dependent on the length of run to the garage and the voltage drop (if you want the welder to run at full capacity).

Here's a really daft suggestion - could you have a 40A changeover switch (shower/welder?)

Cheers

Peter

I too have be wondering if this would be viable. Obviously the shower could now not be used while the welder was in use. But might be a viable option?

dont even go there

 

[CompoSimmonite]

Isn't there some way of having an additional 1 MCB consumer unit next to the existing ?

I'm lucky in that my house was originally 100% electric so has such a spare (redundant when blown heating removed), albeit wire type fuse, supply for the garage

 

[projectwelder]

Yeah. I'm in wales.
Trying to save as much money as posible and do all the labouring/fitting myself.
Fitting a new mains consumer unit with some space would be out of the question I guess as I think I would have to break the mains seals to isolate the main consumer unit.
From what I know that'd be be breaking the law.
But if I could install cable, isolator and socket, I'd guess it'd save a fair bit.
Is it the electricity board that I'd need to contact or can any certified electrician do the job?

 

[doubleboost]

I am by no means well off
I needed a 32 amp supply in the garage
A friend replaced the house consumer unit
Split the tails & installed a consumer unit in the garage
Including the 2 consumer units it was less than £400
(beer is £3 a pint Cigs £ 12 a pack)

 

[projectwelder]

Looks like I best get saving then if I want to use my new welder to full potential. I thought there may have been a more cost effective solution. Without spending all that. A smaller new consumer unit next to the old mains one.

Looks like I will have to get some quotes from a electrician and go from there.

 

[projectwelder]

Hey. Thanks for all the quick replys guys. :-)

 

[brightspark]

-your only other option is change the breaker -to a 20 amp -in house and change that 30 to a 16 in -garage and fit a 16 amp socket for welder

 

[slim_boy_fat]

Can I ask what you're planning to weld in your garage that's going to need the max 250amp with any regularly?

 

[barracuda816]

Most modern service heads have the option of two or more tails from the fused side. Why not take off from there? I Dont know how easy it is to deal with the metering though. You may need another account, i havent done it, so i wouldnt know. It may jjust be another option. Failing that a new conumer unit isnt hard, just get it in quick or you will need a metal one (from Jan).

 

[projectwelder]

I have been repairing some heavy duty gates recently that I would have liked a little more power, also been making pedestal grinder and drill stands for myself and a buddy. It's usually under 5mm thick steel I work with but I wanted the extra power there if needed.
I have looked and 2.5 t&e cable is rated to take 27 amps.
I wonder if I changed the mains breaker to 25 amp type c, and the garage consumer breaker to 16 amps for i could at least use the welder at higher amp but without gettung building control or the electricians involved?

 

[skotl]

Isn't there some way of having an additional 1 MCB consumer unit next to the existing ?

Needs a spark to split the tails though to do it right and its a new circuit then so notifiable to BC..

That's what I had done, although it was a new six way added to the tails as there's no point doing the work and going from a full single box to a full pair of boxes.

I agree with everyone else that the only sensible way (where "sensible" also covers "legal") is to pay a spark to do this. It doesn't cost you anything to get a price so go ahead and get a couple of quotes - you may be pleasantly surprised.

 

[addjunkie]

Im with mr fuzzy here..... By the questions you clearly are not the man to do this yourself, however asking is ok so you are armed with information when discussing with a professional.

My suggestion would be to do the job properly, replace the board, nice modern split job with protection etc, and run a new suitably sized cable out to a garage consumer unit, with 3 mcbs in it 1 for welder, 1 for sockets, and 1 for lights.

I have a 16mm cable goes to my shed, due to distance and load, but a 6 would have done, but got 50 m of the swa 16mm free. (Left over from a job where the plan changed and the cable had alreadt been bought, and my tame sparky owed me some favours, to the tune of 50 hours of my time milling big chunks of billet for his bike)

Only 1 32 amp socket, so i can only run one big load at a time.

 

[puffernutter]

The problem with the 2.5 T&E is not the maximum rating, but the voltage drop (related to the length of your run) when at maximum current.
I've just done a 100m run from the house to my workshop and the calculations showed I needed 16mm sq. to keep the volt drop within tolerance.
Cheers
Peter

 

[barracuda816]

2.5 Twin is ok for 27amps as long as its clipped direct (i believe) if it is in any trunking, through any insulation, bundled ect it will need de-rating plus you need to look at the volt drop. If it was me, i would install a new consumer unit. That Rccb is very highly loaded. Or if you dont want to do that, modify the "outside sockets" circuit and run some armoured 6mm2 (minimum, look at the distance of the run as well as current carrying cap) to the garage consumer unit.

 

[Kayos]

It's one of those "if you have to ask" type questions

I pull cutout fuses all day, it is illegal and dangerous if you are not qualified, and it's not as simple as it first seems

Get a sparky in or risk injuring you or your family, possibly worse