Lots of regs questions

[Markey]

I have lots of questions.


Extension of an existing lighting circuit -
Can one run two sets of 4 x 50w downlights off a radial extension from the lighting circuit on 1mm T&E.

for the switch the wiring will be less than 50mm below the surface but within the safe zone, does this need earthed conduit to protect it?

The cable will be attached to the joists above 100 mm of insulation below 150mm more, is this acceptable?

Extra sockets
Please can you confirm that i am ok to run 3 Double sockets on a spur with a 13a FCU protecting them.
Actually thinking about it i could split the ring at the back of a double socket, replacing it with a single then extend the ring around this new room, are there suitable single gang accessories for this purpose?

Also I believe all of this work does not need Part P as it is an extension of an existing circuit which is permitted.

I am also planning on putting in another spur on the ring in another location that originates from the kitchen but terminates in another room, would this be notifiable?

 

[Cremeegg]

I thought you had recently passed your 2382 which means you should know your way around teh big red book that gives you the answer to all these questions.

 

[Markey]

erm, i think you have me mistaken for someone else. I had a good read of the red book at the library but thats about it.

 

[rebuke]

The switch wiring does not need to be in earthed conduit, assuming the lighting circuit is protected by a suitable RCD.

As for cable, I believe that would come under above a plasterboard ceiling under >100mm of insulation, at which point 1mm looks like it'll be OK (using the calculator here: http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html)

You can run multiple sockets off an FCU as a spur on a ring final yes. As for extending the ring, I'd probably go for some Butt crimps in the back of a socket: http://www.tlc-direct.co.uk/Products/CTBUTTslashB.html

It is all covered by Part P (everything in a domestic property is), but assuming the lights and sockets are not in a kitchen or bathroom (or other special area) then it isn't notifiable.

As for the other spur, if you're doing anything in the kitchen other than like for like replacement, it would be notifiable I believe.

 

[Markey]

thanks for the answers, existing lighting circuit is only protected by mcbs in the CU, is there a simple solution for this or does it have to be done at the CU?

 

[sparkyspike]

is there a simple solution for this or does it have to be done at the CU?

That is the simplest solution!

 

[GaryMo]

thanks for the answers, existing lighting circuit is only protected by mcbs in the CU, is there a simple solution for this or does it have to be done at the CU?

At the CU or before the first piece of concealed cabling you install which is to be less than 50mm from the wall surface.
Ideally you would swap the MCB for an RCBO if your CU supports it.

 

[Markey]

The problem is it is an extension to the existing circuit. I wanted to do it without someone qualified by a competant person scheme and/or the hassle of BC. I doubt i can swap out the MCB in the CU but will look into it.

Also if i have to get BC involved i may as well do the CU at the same time, any idea how much it will cost to get an isolater fitted to the meter tails and how long it normally takes the electricity company?

Many thanks

 

[ban-all-sheds]

As for cable, I believe that would come under above a plasterboard ceiling under >100mm of insulation, at which point 1mm looks like it'll be OK (using the calculator here: http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html)[/QUOTE]
No:

The cable will be attached to the joists above 100 mm of insulation below 150mm more, is this acceptable?

it's Method 101, but that's 10.5A, i.e. OK. Basically unless you introduce grouping or high ambient temperatures it's not possible to bring a 1mm² cable down to under 6A.

thanks for the answers, existing lighting circuit is only protected by mcbs in the CU, is there a simple solution for this or does it have to be done at the CU?

Use BS8436 cable.

 

[Markey]

Use BS8436 cable.

Great, This sounds like a good solution, any suggestions on where to obtain some in less than wholesale sizes?

 

[Markey]

is BS5467 still covered by the 17th? My local qvs shop has this in at a reasonable price if i can use this.

 

[Spark123]

Yeah, but it will be a pain to terminate and the termination should really be accessable.

 

[jaguar1]

I think you will find this work comes under "minor works" and can be registered with building contol as such.

 

[rebuke]

As for cable, I believe that would come under above a plasterboard ceiling under >100mm of insulation, at which point 1mm looks like it'll be OK (using the calculator here: http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html)[/QUOTE]
No:

The cable will be attached to the joists above 100 mm of insulation below 150mm more, is this acceptable?

it's Method 101, but that's 10.5A, i.e. OK. Basically unless you introduce grouping or high ambient temperatures it's not possible to bring a 1mm² cable down to under 6A.

That's what I said - with >100mm of insulation, i.e. Method 101?

 

[ban-all-sheds]

- sorry - didn't read your ">100mm" properly -

I think you will find this work comes under "minor works" and can be registered with building contol as such.

The requirements to notify LABC have absolutely nothing to do with whether BS 7671 classes the work as minor or not, and if work is notifiable there are no different classes, i.e. it's either notifiable or not.