Power to shed. Thoughts?

[DavidSpark]

Good evening everyone,

So I have a "customer" wanting power supplied to an outside shed they are building in the near future which is going to serve as a sort of outside bar type area.

All wiring will be within the shed and the circuits installed will be a radial power circuit and a lighting circuit. I plan to wire these in singles within plastic conduit and have it surface mounted. Nothing special here.

I plan to use 2 core SWA to supply this, either in 2.5mm² or 4mm² (most likely 4 to future proof it.) which will be buried through the garden, most likely installed within cable ducting.

The supply earthing arrangement is PME, so I'm thinking this shed will need to have its own earth rod installed and the earth from the house terminated and isolated from the consumer unit within the shed.

There is a little snag however, and that is the placement of the consumer unit within the property. It is located inside the downstairs toilet, in the top corner. There is no easy way to route cables to this location as the utility room on the other side of the wall has a fully tiled floor. (I have attached a picture of the back door and utility room and the wall which is on the other side from the consumer unit.)

My plan to tackle that would be to run a length of conduit from one wall, onto the ceiling and then back down onto the wall which backs outside (this is a utility room and the "customer" is fine with this arrangement), have this connected to an external weatherproof box and then via appropriate connectors, glands and the likes link onto the SWA which will be clipped direct to the wall and then run down the side of the house and then off to the shed.

This is my first actual domestic setting job, and I'm just wanting a bit input and thoughts from the experience of people on the forums. Would you suggest anything? Do anything differently? I'm interested to hear!




Thanks for reading!

 

[buzzlightyear]

they are building in the near future

what star date year will this be space ranger !

 

[DavidSpark]

Next few weeks.

 

[Leesparkykent]

Good evening everyone,

So I have a "customer" wanting power supplied to an outside shed they are building in the near future which is going to serve as a sort of outside bar type area.

All wiring will be within the shed and the circuits installed will be a radial power circuit and a lighting circuit. I plan to wire these in singles within plastic conduit and have it surface mounted. Nothing special here.

I plan to use 2 core SWA to supply this, either in 2.5mm² or 4mm² (most likely 4 to future proof it.) which will be buried through the garden, most likely installed within cable ducting.

The supply earthing arrangement is PME, so I'm thinking this shed will need to have its own earth rod installed and the earth from the house terminated and isolated from the consumer unit within the shed.

There is a little snag however, and that is the placement of the consumer unit within the property. It is located inside the downstairs toilet, in the top corner. There is no easy way to route cables to this location as the utility room on the other side of the wall has a fully tiled floor. (I have attached a picture of the back door and utility room and the wall which is on the other side from the consumer unit.)

My plan to tackle that would be to run a length of conduit from one wall, onto the ceiling and then back down onto the wall which backs outside (this is a utility room and the "customer" is fine with this arrangement), have this connected to an external weatherproof box and then via appropriate connectors, glands and the likes link onto the SWA which will be clipped direct to the wall and then run down the side of the house and then off to the shed.

This is my first actual domestic setting job, and I'm just wanting a bit input and thoughts from the experience of people on the forums. Would you suggest anything? Do anything differently? I'm interested to hear!

View attachment 36943 View attachment 36944 View attachment 36945


Thanks for reading!

View attachment 36946

what about running it under the plinth of the cupboards cutting a hole and fishing it up the wall to the consumer unit? Being a new build I would of thought they are stud walls? There might be a nogging at around 1200mm so you could cut a 1 gang box in with a multi tool and use a blank plate in the downstairs toilet or put the piece back in you've cut and fill the whole and the customer can tosh the wall which isn't going to be very big in a downstairs WC. Failing that pull the carpet back up stairs and use a solid board cutter and inserts to get a route to outside then conduit down the wall. Conduit across the ceiling will look gash imo and you might have to use metal supports which will make it look even worse. Another solution but not ideal would be to put a switch fuse in the meter cupboard and split the tails with Henly blocks and run the SWA from there.

 

[buzzlightyear]

is that a fly on the wall, black on blue !

 

[Pete999]

Good evening everyone,

So I have a "customer" wanting power supplied to an outside shed they are building in the near future which is going to serve as a sort of outside bar type area.

All wiring will be within the shed and the circuits installed will be a radial power circuit and a lighting circuit. I plan to wire these in singles within plastic conduit and have it surface mounted. Nothing special here.

I plan to use 2 core SWA to supply this, either in 2.5mm² or 4mm² (most likely 4 to future proof it.) which will be buried through the garden, most likely installed within cable ducting.

The supply earthing arrangement is PME, so I'm thinking this shed will need to have its own earth rod installed and the earth from the house terminated and isolated from the consumer unit within the shed.

There is a little snag however, and that is the placement of the consumer unit within the property. It is located inside the downstairs toilet, in the top corner. There is no easy way to route cables to this location as the utility room on the other side of the wall has a fully tiled floor. (I have attached a picture of the back door and utility room and the wall which is on the other side from the consumer unit.)

My plan to tackle that would be to run a length of conduit from one wall, onto the ceiling and then back down onto the wall which backs outside (this is a utility room and the "customer" is fine with this arrangement), have this connected to an external weatherproof box and then via appropriate connectors, glands and the likes link onto the SWA which will be clipped direct to the wall and then run down the side of the house and then off to the shed.

This is my first actual domestic setting job, and I'm just wanting a bit input and thoughts from the experience of people on the forums. Would you suggest anything? Do anything differently? I'm interested to hear!

View attachment 36943 View attachment 36944 View attachment 36945


Thanks for reading!

View attachment 36946

Crikey did you install that SWA?

 

[buzzlightyear]

what with the mash up on the external walls !

 

[telectrix]

can you feed your SWA through the wall units in that utility room?

and what's that cable outside ( above the door ) for, a washing line?

 

[buzzlightyear]

must have put in when he drank a bottle of buck fast !

 

[DavidSpark]

Crikey did you install that SWA?

I did not, done by previous owner sadly. Its fixed with what looks like incorrect sized clips which is why it looks like its drunk!

That's all going to be fixed and tidied up and a new outside light installed.

 

[tomspark93]

Why are you planning on ditching a perfectly good Earthing system for TT? Are there any extraneous conductive parts in the shed? What is going to be powered from the shed as if the Design current isn't much then would a fused spur from the socket circuit suffice? If the design current is higher than 13A and the board is a pig to get too then you could always split the tails in the external meter cabinet and run a new sub main from there.

 

[tomspark93]

Looks like a newish house, is it floor boards or chipboard? Another option if the floor isn't tiled/laminate above the utility room is to take the cable up the external wall and drill through between the ground floor ceiling and first floor and take it through that way and then in to the board.

 

[DavidSpark]

To be honest I am not 100% sure on the rules behind exporting the PME, I was under the impression it wasn't allowed? The shed will be made of wood so no extraneous parts I can think of! I've not got my Regs book to hand so I'd have to look into the rules behind that!

Again that was an option, however I don't know how feasible that will be as the closest outlet (in the conservatory) looks like its already a spur from the RFC.

 

[buzzlightyear]

you could have tied up first before you took the pic .
standards you know.

 

[DavidSpark]

can you feed your SWA through the wall units in that utility room?

and what's that cable outside ( above the door ) for, a washing line?

Quite possible to go that route, but was trying to avoid having to cut out half of the house going horizontal through the wall.

The smaller one is for a sky multiroom, and the SWA is for an outdoor security light.

 

[buzzlightyear]

I've not got my Regs book to hand so I'd have to look into the rules behind that

a brain comes to mind!

 

[DavidSpark]

you could have tied up first before you took the pic .
standards you know.

It's not my house, and I just stopped by to have a look at what there was to work with and I definitely wasn't there to help them with their spring cleaning!

 

[Pete999]

Can you remove the crown molding fitted to the Kitchen cabinets and run the cable in the void?

 

[Pete999]

a brain comes to mind!

Now now Buzz be nice

 

[DavidSpark]

Can you remove the crown molding fitted to the Kitchen cabinets and run the cable in the void?

Looked at that and the cupboards at the top are full length and go right to the ceiling, look custom made so no sneaky void hiding up top by the looks of things sadly!

 

[Pete999]

Looked at that and the cupboards at the top are full length and go right to the ceiling, look custom made so no sneaky void hiding up top by the looks of things sadly!

Well there is some sort of extra wood fastened to the face of those cabinets

 

[LankyWill]

I with @Leesparkykent, fish it under the plinths and through the wall. Solid board cutter route will be just as good, there are blanks specifically designed for the cut out. Export the TNCS as its a perfectly expectable method, just make sure if its PME that there isnt any extraneous bonding in the new shed. Make sure there not going to ask for Infrared heaters as your 4mm will struggle.

 

[buzzlightyear]

one find the socket in the utility area extend to outer wall .
fuse spur in side car case
one gav stop end box outer wall swa and extend to new shed job done .
or ring a friend.

 

[DavidSpark]

Brilliant, thanks very much everyone, lots of food for thought on how to get to done! I'll take a look at getting it under the plinths, I'll hopefully get this done in the "near" future and show you how it went!

Thanks, @Pete999 , @Leesparkykent , @telectrix , @buzzlightyear , @tomspark93 , @LankyWill for your input and experienced advice, very much appreciated!

 

[Pete999]

Brilliant, thanks very much everyone, lots of food for thought on how to get to done! I'll take a look at getting it under the plinths, I'll hopefully get this done in the "near" future and show you how it went!

Thanks, @Pete999 , @Leesparkykent , @telectrix , @buzzlightyear , @tomspark93 , @LankyWill for your input and experienced advice, very much appreciated!

Let us know how you get over the problem

 

[davesparks]

To be honest I am not 100% sure on the rules behind exporting the PME, I was under the impression it wasn't allowed? .

What has given you this impression?
Do you do all of your installation design based on impressions and myths?

 

[Octopus]

Just work to the 18th Ed - export the earth AND install a rod...............

 

[telectrix]

now, now, murdoch. you don't export it, you just extend it.

 

[Leyland30]

As Tomspark mentions - if the 'bar' will only be a small load and it is a pain to route the SWA, then run from a FCU in the house spurred off skt ring. There is a IET Wiring Matters regards this very arrangement - see attached.

Otherwise, unless there specific bonding requirements in the shed i.e. copper water pipe, Jacuzzi; then run a 3C SWA (suggest > 2.5mm^2) - no need for a dedicated rod. (Subject to how far away 'bar' is from house ideally less than 10mtr)

 

[DavidSpark]

As Tomspark mentions - if the 'bar' will only be a small load and it is a pain to route the SWA, then run from a FCU in the house spurred off skt ring. There is a IET Wiring Matters regards this very arrangement - see attached.

Otherwise, unless there specific bonding requirements in the shed i.e. copper water pipe, Jacuzzi; then run a 3C SWA (suggest > 2.5mm^2) - no need for a dedicated rod. (Subject to how far away 'bar' is from house ideally less than 10mtr)

Excellent reading! Thank you for providing it, and your advice.

 

[buzzlightyear]

this site is like Tesco's, every little helps.

 

[buzzlightyear]

where is my points post 31

 

[Simon1979]

Henley block in the meter box and add a 2 way garage cu. SWA from there.

 

[davesparks]

Henley block in the meter box and add a 2 way garage cu. SWA from there.

That's hardly a sensible installation design is it.

 

[Simon1979]

IMO better than spurring from downstairs ring (where applicable). Most home owners want more than just one socket outside eventually so why just give them one when you can have a dedicated radial on its own RCBO. Easier than punching holes in walls through utility rooms too.

 

[davesparks]

IMO better than spurring from downstairs ring (where applicable). Most home owners want more than just one socket outside eventually so why just give them one when you can have a dedicated radial on its own RCBO. Easier than punching holes in walls through utility rooms too.

At least if you spur from the ring you don't leave the installation without a single main switch!
But in all seriousness I don't particularly condone installing a shed supply from a ring either.

Your solution doesn't show any consideration for discrimination. And this thread isn't about installing a single outdoor socket, it's about a submain to a shed.

Just because something is easier it doesn't mean it is the best installation design.