extending SWA

[Benny_Boy]

Evening chaps,

I've got a customer who needs power to a shed. It's going to be 4mm 3core swa cleated along a wall.

His CU is an old RCD isolator MEM.

The plan is swa from main CU to 2x way shed CU.

The cupboard which contains the CU has NO room in it. It's absolutely chokka with isolators for this and that, E7 bits and bobs, meter, service head, 1x way shower, 2x way kitchen CU from recent work, you get the idea.

The net result of this is that the only spare way he's got (in the old MEM board) is inaccessable for terminating SWA in it.

I've got room for an adaptable box in the CU cupboard but not near enough to the CU to butt up to it and I can't get a straight line (or even a bendy line) from the box to the cu for conduit.

Q: Is it within regs to terminate swa on the outer wall in IP56 AB, and go through the wall out the back of the AB with 6mm twin into the CU?

Is there a reg which advises against this mixing cables practise?

chz peeps

 

[telectrix]

perfectly acceptable IMO. suggest 20mm pvc tube round T/E through wall, adaptor into box outside, silicon round between box and wall.

 

[bugsy]

No , IP54 / 56 BOX , CRIMPS OR WAGO'S , BUT IF THE SHEDS IN 4MM THEN 4MM PVC
Im unclear with regards to the position of the RCD ideallly shed should be fed from non RCD consider the exporting of the earth ( distance from house)
RCD ideally in shed

 

[Benny_Boy]

No , IP54 / 56 BOX , CRIMPS OR WAGO'S , BUT IF THE SHEDS IN 4MM THEN 4MM PVC
Im unclear with regards to the position of the RCD ideallly shed should be fed from non RCD consider the exporting of the earth ( distance from house)
RCD ideally in shed

But 4mm swa and 6mm t+E seem to be a better match?

I realize best practice would be an RCBO from CU, or non RCD feed to shed but I've got an RCD main switch to work with or the job won't be happening. (or rather, some cowboy will run a bit of wet string and selotape)

Thanks for your input

 

[Hawk81]

No , IP54 / 56 BOX , CRIMPS OR WAGO'S , BUT IF THE SHEDS IN 4MM THEN 4MM PVC
Im unclear with regards to the position of the RCD ideallly shed should be fed from non RCD consider the exporting of the earth ( distance from house)
RCD ideally in shed

Why does every thread about a shed or garage have to have someone mention exporting the earth even when the op does not ask a question about this.

 

[bugsy]

You havent read the sticky thread entitled shed / garages - anserwing posts

This clearly stated any thread mentioning sheds or garages must contain the phrase exported earth

 

[Engineer54]

Why does every thread about a shed or garage have to have someone mention exporting the earth even when the op does not ask a question about this.

Because they STILL haven't learnt anything that's been posted here recently, about supplying sheds garages and the like!!! They still want to bung a rod in, as soon as you mention shed, garage etc!!...

 

[Hawk81]

You havent read the sticky thread entitled shed / garages - anserwing posts

This clearly stated any thread mentioning sheds or garages must contain the phrase exported earth

I have not. Please put a link to it as I cant find it

 

[thekingiam]

Why does every thread about a shed or garage have to have someone mention exporting the earth even when the op does not ask a question about this.

Lol I was thinking the same! Was waiting for it to be mentioned.

 

[Hawk81]

Can anyone show me this sticky thread i have searched everywhere and cant see it. Its driving me mad

 

[telectrix]

with hawk eyes you should spot it from a mile away

 

[Hawk81]

I know but it is hard to find this time. lol

 

[Deleted member 26818]

Sorry, I didn't realise it was a sticky thread, I thought it was a sticky bun, so I ate it.

 

[thekingiam]

I believe if sticky buns are givenout then they can o nly be given out at a certain electricians pub which i am not dressed for apropriately.

 

[malcolmsanford]

No , IP54 / 56 BOX , CRIMPS OR WAGO'S , BUT IF THE SHEDS IN 4MM THEN 4MM PVC
Im unclear with regards to the position of the RCD ideallly shed should be fed from non RCD consider the exporting of the earth ( distance from house)
RCD ideally in shed

But 4mm swa and 6mm t+E seem to be a better match?

I realize best practice would be an RCBO from CU, or non RCD feed to shed but I've got an RCD main switch to work with or the job won't be happening. (or rather, some cowboy will run a bit of wet string and selotape)

Thanks for your input

As that T+E will be concealed in a wall and certainly parts of it will be less that 50mm buried then you will have to fit an RCD/RCBO to protect it.

 

[johnboy6083]

As that T+E will be concealed in a wall and certainly parts of it will be less that 50mm buried then you will have to fit an RCD/RCBO to protect it.

with regards to the situation that benny boy finds himself, ie drilling directly behind board to a JB, i wouldnt consider anybody stupid enough to try and drill thorugh that! i wouldnt protect that with RCD, if it meant i would have problems with dicrimination with the shed

 

[malcolmsanford]

Unfortunately the Regs don't take into consideration that, even in safe zones where the same logic applies you would not think anyone would drill right above/below a switch or socket, people do, so cable concealed in a wall buried less that 50mm have to be RCD protected Etc Etc.

Agree the chances of anyone drilling into it is small, but it's your name on the cert, and if anything happened to the cable and was not protected to the regs. your the one going to have to explain why you omitted the safety procedures.

Personally I would either try and bring the SWA through the wall. or use a small run of MICC.

 

[johnboy6083]

fair point. I suppose you could use a bit of steel tube. and banjo it at one end,so its earthed. its a lot of messing about though. I cant see why anybody would take the cover off a board, and drill through it, unless they were a spark?

 

[malcolmsanford]

fair point. I suppose you could use a bit of steel tube. and banjo it at one end,so its earthed. its a lot of messing about though. I cant see why anybody would take the cover off a board, and drill through it, unless they were a spark?

If it was easy John everyone would be doing it mate

Between you and me the chances of anything happening to that cable is almost nil, but if your going to work to the regs then you have to sometimes do things that are not the easiest way to get the job done.

There will be some that say do it and mark it on the EIC as a departure from the regs, fine and write out a risk assement to why you omitted the protection as to the regs and attach to the EIC.

Chances are you will get away with it, but to me I'd rather look for a way round it witihn the Regulations, it sometimes is not easy, or quick and can be a pain, but if you do it to the Regs your covered in every way. That's just my opinion though.