Anyone know who sells a kit for wiring my shed. Consumer unit and a few sockets and lights – no heavy duty stuff.

cheers

Never seen a kit and it would be a bit worrying in terms of who the market is. Buying the bits is pretty easy and knowing what to buy is part of doing a safe install. Its not rocket science but you do need to ask the right questions. How are you connecting to your existing supply?

^ quite.

If you know what you’re doing sufficiently to install safely and to code, then you can easily put together a basket of bits at screwfix or toolstation.

what they said.

If you’re fitting a consumer unit in the shed, then you really need to split the meter tails in the house and feed the shed off a separate fuse / RCD (100mA) and then use a 30mA RCD in the shed. Otherwise if you have an earth leakage in the shed, it could trip the RCD in the house which means trekking back in to reset etc….

I was just wondering if a kit was available – lazy option!

I’m connecting to a spare MCB in house consumer unit using 3 core 4mm SWA to reach the shed. 15m from house. Probably don’t need a consumer unit in shed?

cheers

I’m connecting to a spare MCB in house consumer unit using 3 core 4mm SWA to reach the shed. 15m from house. Probably don’t need a consumer unit in shed?

Nope, just some sockets and lights.

You need to use armoured cable or fit it in a conduit and make sure the conduit is earthed if metal.

If the MCB is on an RCD protected circuit then you don’t need a consumer unit locally, or replace the MCB with an RCBO. You can run the sockets on a radial (with the correct rated MCB) then run the lights from a switch fuse. That will give you the issues of tripping that FF mentions so it is often considered good practice to run from a non RCD protected circuit then fit a local RCD/mini consumer unit. Also it will avoid damp in the shed tripping some of your house circuits.

so it is often considered good practice to run from a non RCD protected circuit

Not sure about that especially for an outdoor cable, as you have no RCD protection for someone accidentally cutting through through the cable eg with a power tool etc.

The two simple solutions are a higher leakage current RCD in the house (100mA) or a time delay RCD. Both are allowed under the regs if the user has no access to it ie no sockets / appliances directly off that RCD. All user appliances must be protected by a 30mA RCD.

The cable should be armoured, buried at least 600 mm deep, surrounded by sand and have 6 inch yellow warning tape around 300 mm above it. If you get a power tool through that then you deserve your Darwin Award.

All user appliances must be protected by a 30mA RCD.

Not true

If I have a mini consumer unit in the shed and a higher rated (100mA) MCB in the house does that not cover all eventualities – ie shed MCB trips before the house MCB but should the armoured cable be cut then the house MCB trips?

Probably don’t need a consumer unit in shed?

No, but I would anyway.

And tbh it sounds like you should be getting in a Sparky anyway.

What about if you have a cable (armoured, it really isn’t that expensive and easier than metal ducting) but run it in an easily visible, elevated position? Is that still a no-no?

One option I took on the flat what I ran all the new cables, installed new sockets and switches in position etc – ie did all the dirty work, and then had the electrician in for a day of fitting the new CU and connecting and testing all the new circuits. He had no desire to get get dirty doing all the messy work as he had plenty of jobs on and I use the same company for my gas work so they get repeat work from me.

I would imagine this stuff needs signing off really so that is probably the easiest way to do it and will ultimately make sure you are safe. As others have suggested there is no reason for a kit. It’s a pretty standard thing and the bits are all there to buy.

Not true

Possibly, but to all intents yes you need an RCD.

From Part P (2010), Page 37.

“Nowadays, sensitive RCD protection is required for all socket outlets which are installed having a rating of 32A or less, and which may reasonably be expected to supply portable equipment for use outdoors.”

If I have a mini consumer unit in the shed and a higher rated (100mA) MCB in the house does that not cover all eventualities

If to put a 100mA MCB (sic) in then it should be pretty safe. Might limit what device you can power. Maybe a phone charger. 🙂

And tbh it sounds like you should be getting in a Sparky anyway.

Might be inclined to agree if you are not sure about RCDs and MCBs

I would imagine this stuff needs signing off really so that is probably the easiest way to do it and will ultimately make sure you are safe.

Several options:
1. Get a Sparky to do it and certify it
2. DIY and get a Sparky to inspect, test and certify
3. DIY and pay Building Control to inspect, test and certify (same as 2 but more expensive)

Or

4. DIY and don’t bother with the paper work

4 will be slightly problematic when you come to sell the house though.

Possibly, but to all intents yes you need an RCD.

No, no you don’t. There are special cases, as listed in part P, and certain wiring methods demand it but it is far from a blanket rule. In general I would RCD protect everything with a few exceptions but not because the rules say you must.

From Part P (2010), Page 37.
“Nowadays, sensitive RCD protection is required for all socket outlets which are installed having a rating of 32A or less, and which may reasonably be expected to supply portable equipment for use outdoors.”

Yes there are special cases like circuits that can supply outdoor equipment but that is a long way from ‘all user appliances’. You also need an RCD for sockets installed in a room which contains a shower cubicle. Lots of special cases.

2. DIY and get a Sparky to inspect, test and certify

Not technically allowed. Self certifying sparks can only sign off their own work. You might find one that will let you save a few quid by doing your own digging.

There is also an option 5 which is to design a circuit that can be DIYs and doesn’t need sign off. This would require your current CU to be up to spec and then extending an existing circuit but TBH you’d need to know what you were doing.

I had thought of taking a spur from a socket in the house but thought that wiring into a spare 32A circuit breaker in the CU and on to a separate consumer unit in shed with a 16A and 6A circuit breakers would be better and safer?

I had thought of taking a spur from a socket in the house but thought that wiring into a spare 32A circuit breaker in the CU and on to a separate consumer unit in shed with a 16A and 6A circuit breakers would be better and safer?

It is absolutely better and safer to use a spare circuit and fit a local mini CU but it is also building regs notifiable work. It is daft that the less good solution does not require sign off but such is the law. I was just adding to FF list as an option, but its not one I would choose. There are lots of options so its up to you which path to take.

Thanks far all the advice a options guys – going to wire into the spare circuit breaker and use a mini CU in the shed

cheers

💡

💡

LOL – that’s what I use at the moment – looking for a better solution!!

The cable should be armoured, buried at least 600 mm deep, surrounded by sand and have 6 inch yellow warning tape around 300 mm above it. If you get a power tool through that then you deserve your Darwin Award.

Can’t you surface mount armoured cable? I’ve always cosidered cable that you can see far safer than cable you can’t. I was under the impression SWA cable could be surface mounted along a fence attached to concrete gravel boards for example?

I run one of these RCD plug from B&Q, plugged into a single socket, a heavy duty flex to my shed (about 3m from the house) and a 4 way adapter with a couple of bright LED inspection lamps in the shed.

runs OK, trips out if I overload it (!) can run a small part time heater and a dremel/drill if I need to..

2. DIY and get a Sparky to inspect, test and certify

Not technically allowed. Self certifying sparks can only sign off their own work. You might find one that will let you save a few quid by doing your own digging.

You could use one qualified to do inspection and test, that’s all that BC do, just outsource the job…..

Or

4. DIY and don’t bother with the paper work

4 will be slightly problematic when you come to sell the house though.

And you could do this if you’d owned the house before the regs came in too, but how certain are you that you aren’t going to leave a ‘problem’?

And you could do this if you’d owned the house before the regs came in too, but how certain are you that you aren’t going to leave a ‘problem’?

Especially if you have loads of Black and Red T&E lying around. If not, it’s immediately obvious you’ve changed something post Part P coming into force.

You could use one qualified to do inspection and test, that’s all that BC do, just outsource the job.

Yes, but all they can do is inspect and test it. They can’t register it as a spark would self certify. You’d then need to go through building control anyway. There was talk of starting a scheme where people could inspect and certify but as far as I am aware this never happened.

Gonna get shot down here, but I run a waterproof/exterior cable out to my shed inside a bright blue hosepipe which is attached to the fence about 12″ off the ground. I plug it into an RCD as I go to the shed, and unplug it once I’ve come back in. I run a single bulb off it, and occasionally a drill too. If I sell the house, I’ll remove the cable. I haven’t died.. yet.

I plug it into an RCD

If it is really just plugged in you can just leave an unprotected cable lying on the ground for ever and it’s all perfectly ‘OK’. It’s only if you wire it when the regs start to apply…

Ah ok. Thanks.

inside a bright blue hosepipe

Although I would say that would be rather daft choice of conduit as you’re hiding a potentially dangerous cable in what looks like a water pipe. Eg if the worst happens, you wouldn’t have a leg to stand on if someone prosecuted you for negligence (or whatever charge they threw at you subsequent to someone having died after cutting through it).