Garage fuse box installation, what type breaker and main feed cable size?

[MaxtheWeld]

Hi everyone,

I bought a welder before Christmas but I can't use it as I am not sure about the electricity in my garage.

The garage fuse box has one B 6, one B 16 and 2 red switches with 63amp on them. The cable feeding the fuse box in the garage is 600/1000V BS5467 3x2.5 which I belive is 3 core 2.5mm cable. Also the welder I bought is 240V, EWM Tetrix XQ 230 Puls AC/DC which came with 16amp blue plug and 2.5 mm cable.

To use this welder, what do I need to change in my garage?

Thanks in advance.

 

[skotl]

Welcome to the forum

Your distribution board has a 6 amp "B Curve" breaker, for the lights, and a 16A B Curve breaker for the 13 amp sockets. The big red thing is a single switch rated at 63A to protect the rest of the board.
You can likely run the welder on a 16A circuit, although 32A would be better (its plate suggests that it needs 28.1A at full chat).

As you don't have any space left in the distribution board then your best bet is to get an electrician to replace it with one that will take an additional breaker or two, then have them fit a C32 breaker to supply a dedicated 32A run for the welder. You will then need to swap the blue plug on the machine for a 32A one (which looks similar to, but is physically larger than the 16A one). This is all far cheaper than it might sound: way less than £100 for the board, another MCB and a 32A plug - the more expensive part will be the electrician's time.

Realistically, you can run the welder on a smaller-rated circuit if you keep away from its maximum power ratings - you might get up to around 100A of welder output on a 13A plug. That said, the B Curve breakers you have in there are designed to trip faster than a C Curve one, so you might find that the B16 trips often when you're using the welder. If it was me, I'd replace the 16A blue plug with a standard 13A "home" plug and give it a go. Worst case is the breaker trips and you know you need to wait until the electrician comes in!

Edit: if the cable feeding the board really is 2.5mm then you have a problem as that isn't rated for 32A - the electrician would need to replace that run, too. You should be able to guesstimate its rating by looking at whatever the breaker in your house board has that supplies the garage feed (assuming the electrician did it correctly and matched the breaker to the cable!).

 

[Barking Mat]

Probably stick a 32 amp MCB, in your DB, and a blue 32 amp commando plug, then your laughing.

 

[brightspark]

your

Welcome to the forum

Your distribution board has a 6 amp "B Curve" breaker, for the lights, and a 16A B Curve breaker for the 13 amp sockets. The big red thing is a single switch rated at 63A to protect the rest of the board.
You can likely run the welder on a 16A circuit, although 32A would be better (its plate suggests that it needs 28.1A at full chat).

As you don't have any space left in the distribution board then your best bet is to get an electrician to replace it with one that will take an additional breaker or two, then have them fit a C32 breaker to supply a dedicated 32A run for the welder. You will then need to swap the blue plug on the machine for a 32A one (which looks similar to, but is physically larger than the 16A one). This is all far cheaper than it might sound: way less than £100 for the board, another MCB and a 32A plug - the more expensive part will be the electrician's time.

Realistically, you can run the welder on a smaller-rated circuit if you keep away from its maximum power ratings - you might get up to around 100A of welder output on a 13A plug. That said, the B Curve breakers you have in there are designed to trip faster than a C Curve one, so you might find that the B16 trips often when you're using the welder. If it was me, I'd replace the 16A blue plug with a standard 13A "home" plug and give it a go. Worst case is the breaker trips and you know you need to wait until the electrician comes in!

the feed to the db s only a 2.5mm cable its max load will only be 25 amp max and would need up rating anything bigger

 

[skotl]

your

the feed to the db s only a 2.5mm cable its max load will only be 25 amp max and would need up rating anything bigger

Yep - spotted that and edited an addendum just as you typed this
It would seem pretty short-sighted of any spark running just 2.5mm to a garage board, though, wouldn't it

 

[Robotstar5]

Yep - spotted that and edited an addendum just as you typed this
It would seem pretty short-sighted of any spark running just 2.5mm to a garage board, though, wouldn't it

I only had 1.5mm SWA feeding mine, I upgraded it to 6.0mm

 

[MaxtheWeld]

Thanks for the very quick replies! Much appreciated!

So basically I need to change/upgrade everything. A new cable for feeding the garage fuse box (6mm?), a new fuse box with 32amp type C breaker, a new cable and 32amp plug for welder?

The one thing I don't understand, why a welding supply company would put a 16amp plug and 2.5mm cable on a 230amp AC/DC welder. Shall I contact them and ask them why?

 

[brightspark]

got a 35mm armoured cable feeding my garage only because i got it for nowt a 6.0mm cable would have been put in on a 42 amp breaker if i had to buy it and thats well sufficient for your needs

 

[skotl]

Thanks for the very quick replies! Much appreciated!

So basically I need to change/upgrade everything. A new cable for feeding the garage fuse box (6mm?), a new fuse box with 32amp type C breaker, a new cable and 32amp plug for welder?

The one thing I don't understand, why a welding supply company would put a 16amp plug and 2.5mm cable on a 230amp AC/DC welder. Shall I contact them and ask them why?

Mostly, yes.

You don't need "a new cable and 32a plug for the welder", just a new 32A plug (the cable will be correct as that is fitted by the manufacturer). To be honest, the retailer is damned if they do, damned if they don't: they could have supplied it with no plug, or a 16A or a 32A one.
A new 32A plug isn't expensive though so I wouldn't worry about that.

I do still have a question mark over your assumption that both the welder cable and the garage feed are 2.5mm - the welder's cable definitely won't be, so I wonder how you're measuring / guessing the garage cable

No biggie, though - getting an electrician in will allow him/her to verify it quickly enough. If the garage is attached to the house (so no need for underground / armoured cable) then 4mm or 6mm cable is less than £2 a metre.

 

[Dave-sparks]

So basically I need to change/upgrade everything.

No, you need a competent person to assess what you have and advise you from there.

 

[willie.macleod]

What are you actually wanting to weld with it? If you are using your new welder for shorter periods and for welding thinner materials such as sheet materials then it is likely to work just fine using the likes of this commando adapter - https://www.halfords.com/camping/electrical-and-power/w4-mains-hook-up-adaptor-uk-710620.html

If you are an expert, i.e, you spend more time welding than grinding electrodes then yes an upgrade to the shed supply is in order if you want to use your new toy to its full capacity. In the meantime, get the thin stuff out and enjoy it!

 

[addjunkie]

No, you need a competent person to assess what you have and advise you from there.

I agree with this, as there are many other factors such as the distance to the supply, and its route that come into play. But I am sure the flex on the welder will be fine for the load it will draw. Dont forget the quoted 28 amps is the initial surge or inrush and wont be sustained.

I have it in my head that flex can carry more load than similar sized twin and earth, but dont know where I got that from. Sure google will clarify.

But as your so unsure I think you should just sell me the machine cheap and buy yourself a smaller one that'll save you running a new cable to your garage.

 

[Dave-sparks]

I have it in my head that flex can carry more load than similar sized twin and earth, but dont know where I got that from. Sure google will clarify.

No/yes/maybe

It all depends on the type of insulation and sheath the fiex has, along with the conditions it is being used in.

 

[markythesparky]

where is the supply fed from and is it on its own breaker or jut spured of the house ringmain

 

[aesmith]

The one thing I don't understand, why a welding supply company would put a 16amp plug and 2.5mm cable on a 230amp AC/DC welder. Shall I contact them and ask them why?

That flex on the welder is marked H07RN-F so if that's 2.5sq.mm as you say, it will be good for around 25 amps. Checking with the supplier might be a good idea, the fact that they supply with a 16A plug suggests they think it should be OK on a 16A supply.

 

[Misterg]

The one thing I don't understand, why a welding supply company would put a 16amp plug and 2.5mm cable on a 230amp AC/DC welder.

From your photo of the rating plate, the required supply (Ieff ) is 16 amps, so plug/cable would seem appropriate

 

[prepman]

Thanks for the very quick replies! Much appreciated!

So basically I need to change/upgrade everything. A new cable for feeding the garage fuse box (6mm?), a new fuse box with 32amp type C breaker, a new cable and 32amp plug for welder?

The one thing I don't understand, why a welding supply company would put a 16amp plug and 2.5mm cable on a 230amp AC/DC welder. Shall I contact them and ask them why?

Is your garage integral to the house and does it have 2 x 2.5mm² cables i.e. ring main? It doesn't have an ELCB/RCCD in that CU. Or is it completely detached? That I think is the difference to it being an outbuilding which comes under different regs. I don't have copy of the latest regs.
My garage has a 32amp breaker so the 32A welding socket is connected as part of the ring on an ELCB/RCCD protected system.. Your welder is rated normally at 16A with inrush of 26A.
As neither the 16A or 32A sckets are fused your relying on the MCB.

 

[MaxtheWeld]

Mostly, yes.

You don't need "a new cable and 32a plug for the welder", just a new 32A plug (the cable will be correct as that is fitted by the manufacturer). To be honest, the retailer is damned if they do, damned if they don't: they could have supplied it with no plug, or a 16A or a 32A one.
A new 32A plug isn't expensive though so I wouldn't worry about that.

I do still have a question mark over your assumption that both the welder cable and the garage feed are 2.5mm - the welder's cable definitely won't be, so I wonder how you're measuring / guessing the garage cable

No biggie, though - getting an electrician in will allow him/her to verify it quickly enough. If the garage is attached to the house (so no need for underground / armoured cable) then 4mm or 6mm cable is less than £2 a metre.

Sorry guys, I've had few busy weeks and totally forgot about this thread.

Welder still sits in the garage and I didn't have the chance to play with it but I will sort it out next weekend.

The cable feeds the garage is Nexans PVC armoured BS 5467 3x2,5mm2 cable and outer diameter is 13mm; here is some specifications:

https://www.nexans.co.uk/eservice/UK-en_GB/pdf-product_540168750/CU_XLPE_SWA_PVC_BS_5467_3x2_5_mm2.pdf

Welder cable is Pecso MN IEMMEQU H07RN-F 3g2,5mm2 and outer diameter is 14mm, you can see some specifications if you go to this link and check IH7N03025 3x2,5:

H07RN-F – Pecso Cavi

www.pecso.it

So I think the cables are okay but I still need to change the breakers to 32a ones.

 

[AVI_8]

Sorry guys, I've had few busy weeks and totally forgot about this thread.

Welder still sits in the garage and I didn't have the chance to play with it but I will sort it out next weekend.

The cable feeds the garage is Nexans PVC armoured BS 5467 3x2,5mm2 cable and outer diameter is 13mm; here is some specifications:

https://www.nexans.co.uk/eservice/UK-en_GB/pdf-product_540168750/CU_XLPE_SWA_PVC_BS_5467_3x2_5_mm2.pdf

Welder cable is Pecso MN IEMMEQU H07RN-F 3g2,5mm2 and outer diameter is 14mm, you can see some specifications if you go to this link and check IH7N03025 3x2,5:

H07RN-F – Pecso Cavi

www.pecso.it

So I think the cables are okay but I still need to change the breakers to 32a ones.

No you can’t run 32 amps through a 2.5 MM cable, you’ll melt it.
You'll need a 6mm cable. (legally)
Edited to say a lighting circuit, ring main and a 32 amp socket through a 2.5 MM cable

 

[brightspark]

max 25 amp on the 2.5mm cable depending on how installed 4.0mm for the 32 amp