workshop/shed power

[ericmark]

1.5kW motor may start with 13A it could also trip. Theory says 16A blue sockets but in practice a B16 MCB will likely trip before a 13A fuse. Which means a C16 MCB and this will trip with the same instant current as a B32 MCB but with a welder it depends how much welding is done.

As to a B40 supplying whole shed yes it would be my aim to have a larger MCB in the house to any MCB in the out building even if some times the house may trip first.

So if going for a 40A MCB in house then 6mm SWA and 10mm T&E is the minimum size and assuming a B40 then loop impedance of 1.15Ω to satisfy that you need to know value in the house.

For lighting to comply with 6mm cable max length around 21.5 meters assuming incoming at 0.35Ω the destination should be around 0.52 Ω if going for power only then should be OK for around 37 meters and the destination impedance around the 0.64 Ω mark. A type C40 MCB is requiring 0.57 Ω impedance so cable length 31 meters.

Can't remember how far you said it was jump to 10mm and limit is 54 meters. Remember I am assuming at the house consumer unit reading is 0.35 Ω or better. I have also taken into account correction figures. Working on installation method C.

I would be wary of going to the limits. You clearly want it to pass. As to lights using LED or HF florescent unlikely to be a problem even if volt drop not complied with.

 

[skotl]

So it's not a good idea to have for the compresser and welder to have there own circutis


The compresser has a 13amp plug also

It doesn't seem likely that you'll be running both at the same time, so I can't see why you'd want them on different circuits.

Just have your spark run a 13A ring.

 

[ericmark]

Just have your spark run a 13A ring.

Why would anyone run a 13A ring? We would call it a radial or a spur at 13A.

A ring is normally 32A but a B32 has the same magnet trip as a C16 so if a B32 holds in so will a C16. Where the difference comes in is is drawing current over a long time. A C16 will supply 18 amp for longer than a 13A fuse and when it trips easier to reset than changing a fuse.

So fitting a 16 amp radial allows you to use 16A sockets so you can weld for longer without the MCB tripping. Also no need for a ring likely single radial if you want compressor and welder together then two 16A radials but can't really see you doing air arc!

 

[scott25]

i would be doing much welding I would be useing my compresser more but more then likely I would be useing the normal tools. I just want to make sure I do it once and it's right if u understand

Is the wylex insulated box with the rcd 5way a good cu for my shed I think I would have to get most off my bits from tlc which i don't mind as I still get me discount

As am finding it hard to find the metal clad box

 

[ban-all-sheds]

I been on other diy forums and no seems to want to give advise

Thanks to Eric's detective work we now know that that isn't quite true. We now know that you asked on another forum over a year ago, where you did actually get quite a lot of advice on cable size, installation etc. And advice about needing an electrician to actually be in charge and tell you what to do.

We now know that for some reason you did nothing, and then recently asked the same questions all over again on that other forum. And again you got a lot of advice about needing an electrician to actually be in charge and tell you what to do.

Have you noticed a very common theme running through the answers you've been getting, in different places, for the last 18 months?

There is s sparky doing the work I could did it myself but am not part p so am doing all the leg work

Fair enough.

You should be able to find one quite happy for you to dig the trench (few electricians are wannabe navvies), and possibly do other bits of labouring, but you must get him on board first, and everything you do must be under his supervision and direction. In other words the job must be his from start to finish with him using you as his labourer. It will also save you a few £00 in LABC fees.

I suggest you find your sparky right now, have him do the brain work (ie the things you don't know about). Have him agree what you can do yourself and then he can oversee your bit, do his bit and sign it off.

As has been said, I think that by far the best approach would be for you to involve an 'self-certifying' electrician soon, and discuss with him/her what parts of the work you can do (whenever), and what degree of involvement and 'supervision' on the part of the electrician will be necessary in order for the electrician to be able to 'sign off' and notify the work.

i would be doing much welding I would be useing my compresser more but more then likely I would be useing the normal tools. I just want to make sure I do it once and it's right if u understand

Fine - then tell your electrician what tools you will be using, and how, and he will design the installation in your workshop appropriately. He has to be the one to do that anyway, as otherwise he cannot sign the EIC and he cannot tell your LABC that he complied with the Building Regulations.

Is the wylex insulated box with the rcd 5way a good cu for my shed

That's a design question which only the electrician doing the job may answer.

As am finding it hard to find the metal clad box

The electrician doing the job will decide, after seeing the environment, whether you need a metal CU or not, and he'll be able to source the appropriate components and materials.

I been on other diy forums and no seems to want to give advise

I have to say that, given the way you are persisting in asking questions which do not fit in with your assertion that you will actually be using an electrician to do this job, I'm beginning to think that what you mean is that nobody seems to want to give you the advice you have decided in advance is the advice which you want.

 

[JohnW2]

Just have your spark run a 13A ring.

Why would anyone run a 13A ring? We would call it a radial or a spur at 13A.

I suspect that there is some slightly sloppy language at work here, and that what skotl actually meant was a 'standard (32A) ring', with 13A sockets, rather than any dedicated circuits with 16A sockets. I may, of course, be interpreting him incorrectly!

Kind Regards, John

 

[skotl]

Yes - that ^^^ - thanks, John.

 

[JohnW2]

Yes - that ^^^ - thanks, John.

You're welcome - I thought as much!

Kind Regards, John

 

[scott25]

I been on other diy forums and no seems to want to give advise

Thanks to Eric's detective work we now know that that isn't quite true. We now know that you asked on another forum over a year ago, where you did actually get quite a lot of advice on cable size, installation etc. And advice about needing an electrician to actually be in charge and tell you what to do.

We now know that for some reason you did nothing, and then recently asked the same questions all over again on that other forum. And again you got a lot of advice about needing an electrician to actually be in charge and tell you what to do.

Have you noticed a very common theme running through the answers you've been getting, in different places, for the last 18 months?


U should work for the old bill lol I ask when I was building my brothers gym I can post the link if u would like but this time it for my own work shop I didn't know it would be a prob asking questions well thanks for all your help I have nothing to hide I can post picks off my brothers gym project from start to finish

There is s sparky doing the work I could did it myself but am not part p so am doing all the leg work

Fair enough.

You should be able to find one quite happy for you to dig the trench (few electricians are wannabe navvies), and possibly do other bits of labouring, but you must get him on board first, and everything you do must be under his supervision and direction. In other words the job must be his from start to finish with him using you as his labourer. It will also save you a few £00 in LABC fees.

I suggest you find your sparky right now, have him do the brain work (ie the things you don't know about). Have him agree what you can do yourself and then he can oversee your bit, do his bit and sign it off.

As has been said, I think that by far the best approach would be for you to involve an 'self-certifying' electrician soon, and discuss with him/her what parts of the work you can do (whenever), and what degree of involvement and 'supervision' on the part of the electrician will be necessary in order for the electrician to be able to 'sign off' and notify the work.

i would be doing much welding I would be useing my compresser more but more then likely I would be useing the normal tools. I just want to make sure I do it once and it's right if u understand

Fine - then tell your electrician what tools you will be using, and how, and he will design the installation in your workshop appropriately. He has to be the one to do that anyway, as otherwise he cannot sign the EIC and he cannot tell your LABC that he complied with the Building Regulations.

Is the wylex insulated box with the rcd 5way a good cu for my shed

That's a design question which only the electrician doing the job may answer.

As am finding it hard to find the metal clad box

The electrician doing the job will decide, after seeing the environment, whether you need a metal CU or not, and he'll be able to source the appropriate components and materials.

I been on other diy forums and no seems to want to give advise

I have to say that, given the way you are persisting in asking questions which do not fit in with your assertion that you will actually be using an electrician to do this job, I'm beginning to think that what you mean is that nobody seems to want to give you the advice you have decided in advance is the advice which you want.

 

[scott25]

I have nothing to hide I been on other forum when I was asking about my brothers gym so am asking questions about my workshop am sorry about asking questions and advise that's the problem with forums people are to quick judge I will post pics off my brothers gym from start to finish I have nothing to hide

 

[ban-all-sheds]

I have nothing to hide I been on other forum when I was asking about my brothers gym.

Maybe you have, but the other forum posts I was referring to above:

I been on other diy forums and no seems to want to give advise

Thanks to Eric's detective work we now know that that isn't quite true.

were not about your brother's gym, they were about your shed/workshop, and installing electrics to and in it.

so am asking questions about my workshop am sorry about asking questions and advise that's the problem with forums people are to quick judge

I don't think people are being quick to judge.

But you do keep asking questions which show that you are not listening to all the people telling you that you have to get an electrician involved before you do anything, and you must let him take charge, make decisions and, if you are to do any of the work, be the one to tell you what to do, and supervise it.

 

[aesmith]

Just noticed Scott25 is in Wales. Are the rules the same as England regarding Local Authority notification (ie have to notify almost anything)?

 

[Bluehair]

Hi new to the forum

I been on other diy forums and no seems to want to give advise I hope someone can help

I have a 12x8 shed/workshop at the bottom off my garden and I would like to run power to it I have a blangdon power safe in there at the moment but there is only some tools I can use.

The power tools i will be using is compressor and a welded both i been using on the blagdon set up as both have 13amp plugs and a 1kw heater they r not use all at the same time thou.

The shed is about 30ft max for my back door and 58ft to the cu in the house heres where the problems begin.

I cant run 6mm swa in the house as the route i have to run swa would just not be idle but in the garden swa would in a trench feed thou solvert weld pipe then gravel on top off that then warning tape and the back filled with top soil.

Can i run 6mm t&e from the house cu to the 6mm swa i been reading up that i would need a metal junction box for this ?

then can the swa go straight in the cu in the shed/workshop or would it have to be done back to t&e

wot cu for the workshop would be good would it have to be metal or can i use a insulated plastic cu

can the welder/ compressor have there own fuse in the cu same with the heater

i have been told i can use the electric cooker fuse in cu in the house as it not used is that true if so how would it be possible to do so

am sorry about all the questions i hope u don't mind me asking

i done quite abit off electrical work before which have all pass when tested

i want to do all the labour work myself then get sparky to connect it to the house cu

You have been asking the same question on various forums for over a year.

 

[ban-all-sheds]

Just noticed Scott25 is in Wales. Are the rules the same as England regarding Local Authority notification (ie have to notify almost anything)?

No, but in both jurisdictions new circuits and CUs are notifiable.

 

[aesmith]

OK so if the shed CU was already installed, would additional circuits in the shed be notifiable? Just wondering if he could do what I've done in the past, got an electrician to put in the CU and connection back at the house, leaving me to install the final circuits.