A few questions for you

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moonpig

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I was replacing some lights and cracked 3 gang light switch today, the the switch feed from one cieling rose was shared between each individual switch and having only the switch live coming from the 2 other ceiling roses (i hope you understand what i mean although i probally didnt explain it that well, so feel free to ask any questions).

Is this bad practice? (never seen it before but i am new to the sparking game and have mainly done new builds)

Should it be updated?

Also what do you more exerienced sparks think or running cables for additions to a ring main behind the skirting boards? (i do mean the type designed for allowing cables to be run) is this bad practice? the house is occupied the house owner doesnt want the floor boards pulled up or large chases in the walls.

If the skirting boards is a good idea does anyone have any links to some decent ones?

Last but not least when running cables behind skirting, to my understanding this is outside the 'safe zones', what would your interupretation be (i.e to comply with regs).

Like i said i am a new young and aspiring spark and i ahve never used the skirting method before, so any help would be great.

Thanks.

 

kme

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I was replacing some lights and cracked 3 gang light switch today, the the switch feed from one cieling rose was shared between each individual switch and having only the switch live coming from the 2 other ceiling roses (i hope you understand what i mean although i probally didnt explain it that well, so feel free to ask any questions).Understand ok. It isn`t the way I generally do mine; but it isn`t an issue.

Is this bad practice? (never seen it before but i am new to the sparking game and have mainly done new builds)

not AFAIAC

Should it be updated?

WHY?

Also what do you more exerienced sparks think or running cables for additions to a ring main behind the skirting boards? (i do mean the type designed for allowing cables to be run) is this bad practice? the house is occupied the house owner doesnt want the floor boards pulled up or large chases in the walls.

If that is the best possible place, given the customer`s considerations, so be it. Not a problem, as far as I am concerned!

If the skirting boards is a good idea does anyone have any links to some decent ones?

Decent what? Skirting boards??

Last but not least when running cables behind skirting, to my understanding this is outside the 'safe zones', what would your interupretation be (i.e to comply with regs).

Would agree that within 150mm of floor is not a "safe zone".

Like i said i am a new young and aspiring spark and i ahve never used the skirting method before, so any help would be great.

Thanks.
No problem, and welcome along.

 

SPECIAL LOCATION

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IAlso what do you more exerienced sparks think or running cables for additions to a ring main behind the skirting boards? (i do mean the type designed for allowing cables to be run) is this bad practice? the house is occupied the house owner doesnt want the floor boards pulled up or large chases in the walls.

If the skirting boards is a good idea does anyone have any links to some decent ones?

Last but not least when running cables behind skirting, to my understanding this is outside the 'safe zones', what would your interupretation be (i.e to comply with regs).

Like i said i am a new young and aspiring spark and i ahve never used the skirting method before, so any help would be great.

Thanks.
Hi Moonpig,

Just to add a few more thoughts you may want to consider..

IMHO

Skirting board that is designed to carry electrical cables.. would be considered as a form of surface trunking..

i.e. the cables are NOT behind the skirting...

They are INSIDE the skirting & the skirting is surface mounted on the fabric of the buiding...

therefore safe zones.. which relate to concealed cables buried into the fabric of the building do not apply.

Tend to be more common in commercial & office environments...

some types may look a bit naff in a domestic property?

They normally have segregated channels for Power, telecoms & data circuits..

Not sure how you will branch off to individual socket without making the room look to much like an office with loads of white trunking???

 

moonpig

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Thanks for your replys guys.

KME the reason i thought the lights might need updating is because i remember talking to another spark a couple of years ago and he was complaining about a 'borrowed neutral' which needed updating. I cant remember the exact specifics of the situation he was describing because i never saw the job and have never seen it for myself, so my brain logged the borrowed neutral part but the fine details.

When i first saw the shared common the 'borrowed neutral' sprang to mind, and although i knew it was safe and functioned fine i was a little unsure to if it complyed with the regs. As a young spark i am still fully familiarising myself with all the regs and how to interpret them in certain circumstances, thankfully you guys are helping me with that:D.

Special location, thanks for explaining the regs side of things. I know the trunking skirting for commercial,industrial use you mentioned, i atually installed some on my first couple of weeks of electrical work in a school/college, and i agree it would not look good in a domestic property.

I am going to look for something more suitable tommorrow and if i find something decent post a link to see what you think.

The way i was thinking about running it is chase the spurred cable into the wall dropping down to the skirting board run the cable to the new socket location which is on a stud wall, run the cable into the stud wall cavity and up to the socket cavity wall box. That way there wont be any visable trunking (apart from the purpose made skirting), and so shouldnt look too bad (or like an office:D). I should be able to get away with one little 750mm chase without the home owner complaiing to much.

What do you think? Does that sound like a good idea?

 

kme

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Appreciate point on borrowed neutral, but in this case, we`re on a "shared live / line / phase (delete as you prefer the terminology!) :)

I think our Mr. Special got confused (bless `im, `ees only just come back from

"dahn sahf!"). I think we`re on cables behind standard skirting board, not within hollow upvc stuff. I have put cables behind skirting; less than 150mm from FFL, and AFAIAC it isn`t an issue.

 

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Appreciate point on borrowed neutral, but in this case, we`re on a "shared live / line / phase (delete as you prefer the terminology!) :) I think our Mr. Special got confused (bless `im, `ees only just come back from

"dahn sahf!"). I think we`re on cables behind standard skirting board, not within hollow upvc stuff. I have put cables behind skirting; less than 150mm from FFL, and AFAIAC it isn`t an issue.
I am going to have to disagree with you on this one bud! :(

IMHO

a cable running along a wall, fixed to that wall,

which is not visible or enclosed in visible trunking or conduit is be definition concealed within the wall fabric & decor

thus reg 522.6.6 (522-06-06 old money)

concealed cable route depth less than 50mm

safe zones..

150mm from TOP, or 150mm from corners formed by adjoining WALL,

or vert or hoz from accessory..

but NOT 150mm from floor!?

tis the way I read it!

I never run cables behind skirting...

too much risk of joe public coming along banging a nail or screw though cuz the skirting has warped a bit from the wall! :(

or they are fixing something to the skirting! :eek:

that tis my opinion for what tis worth! :)

I wont call you a GIT.... cuz now you have Mrs KME to double your rank..

I ain't gonna argue! :D :^O:^O:^O:^O:^O:^O

 

moonpig

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Ok brace yourselfs because here comes a whole barrage of questions.

Could you elaborate on the whole 'borrowed neutral' thing a little? Maybe an example of a case you have seen. (i guess it is when a neutral is borrowed from a different seperate circuit).

Also could you explain why a shared phase (i will pick phase from your list because my old boss used to go ape **** if i used any other different terminology:D) is ok but a brrowed neutral isn't? Would i be right to assume that is has something to do with the shared phase all being on the same circuit, and that it is only really permitted/practiced on lighting circuits?

Right back to the ring main additions job. I also inturpret the regs that 150mm up from FFL is not a safe zone ,i am in no way saying you are wrong KME, just how i understand it; (mainly from the diagram in the OSG).

Obviously you guys understand the regs better than me so i hope you can answer a couple of questions for me which have sprung to mind after reading your replys.

If you run cables behind normal skirting boards buried in the wall more than 50mm, then the cable run complys with regs yes?

Can you run cables anywhere you want so long as they are buried more than 50mm?

If cables are buried more than 50mm in the wall, you still cant run cables diagonally and must run them horizontally or vertically?

You can surface run conduit/trunking anywhere you want? (obviously within reason, no PVC conduit in a workshop or working garage etc)

Cables clipped direct still have to be run in safe zones? (seems a little bit odd as it is very similar to surface run conduit/trunking, and theres not much chance of someone drilling through a clipped direct cable)

Sorry if the questions are stupid, and sorry for so many of them, but they should be nice and easy to help ease you out of your hangover:D.

 

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Ok brace yourselfs because here comes a whole barrage of questions.
At this point I am tempted to say... "bug9er off" I was about to go to bed! :^O :^O:^O

here goes my opinion for what its worth....

Could you elaborate on the whole 'borrowed neutral' thing a little? Maybe an example of a case you have seen. (i guess it is when a neutral is borrowed from a different seperate circuit).
yep thats it... just to elaborate a bit further...

Reg 314.4

every final circuit must be electrical seperate from every other final circuit' date=' to prevent indirect energising of an isolated circuit. (2:00am paraphrase version!)

once a "live/phase/line" conductor leaves an MCB at the CU out to switch & load, it must not be connected back to any other circuit only back to the neutral bar at the CU!

the common borrowed neutral situation is two lighting circuits UP & DOWN stairs,

have neutrals joined at some point between the two-way landing/hall switching,

due to the concept of a physical downstairs switch operating a physical upstairs light.

it can be logically argued that the landing light could belong to either upstairs or downstairs circuit

what often ends up is a live from the one circuit goes through the bulb to a neutral off the other circuit....

So risk of power still being present at some point on the circuit if only one of the fuses is switched off! thus risk of electric shock!

which is not good! :(

Also could you explain why a shared phase (i will pick phase from your list because my old boss used to go ape **** if i used any other different terminology:D) is ok but a brrowed neutral isn't? Would i be right to assume that is has something to do with the shared phase all being on the same circuit, and that it is only really permitted/practiced on lighting circuits?
shared phase would be Two mcb fuses providing supply onto the same circuit..

I have seen this where some plonker has joined two radial socket circuits together at a remote part of the installation!

Again REG 314.4 says big NO NO ! as common sense also does! ;)

Right back to the ring main additions job. I also inturpret the regs that 150mm up from FFL is not a safe zone ' date='i am in no way saying you are wrong KME, just how i understand it; (mainly from the diagram in the OSG).

[u']Obviously you guys understand the regs better than me so i hope you can answer a couple of questions for me which have sprung to mind after reading your replys.
Allegedly! :eek: :| :p

If you run cables behind normal skirting boards buried in the wall more than 50mm' date=' then the cable run complys with regs yes?

Can you run cables anywhere you want so long as they are buried more than 50mm?

[/quote']

Yes greater than 50mm is fine to comply with electrical regs BS7671.... BUT.....

you would need to check with the building structure & general building regs regarding how deep you could take a chase..

i.e. Chases in a structure Approved document A (2004) states...

1] Vertical chases should be not deeper than 1/3 of wall thickness or in cavity walls 1/3 of leaf thickness

e.g brick must be greater than 150mm if you are chasing to 50mm!

2] Horizontal chases should not be deeper than 1/6 of wall or leaf.

e.g brick must be greater than 300mm if you are chasing to 50mm!

(that a brick about 1ft thick!!!!!!!!)

3] Chases should not impare the stability of the wall particularly where hollow bricks are concerned!

So in a nutshell the wiring & building regs are NOT telling you to chase to 50mm...

They are saying RCD protect all buried cables and just use normal chase depths below plaster!

If cables are buried more than 50mm in the wall' date=' you still cant run cables diagonally and must run them horizontally or vertically?

[/quote']

IF they are greater then 50mm you can run where the heck you like..

but see previous point... is your wall structure thick enough???

You can surface run conduit/trunking anywhere you want? (obviously within reason' date=' no PVC conduit in a workshop or working garage etc)

[/quote']

PVC conduit is fine for workshop & garage.. High impact PVC stand a fair few knocks & bumps. ;)

Cables clipped direct still have to be run in safe zones? (seems a little bit odd as it is very similar to surface run conduit/trunking' date=' and theres not much chance of someone drilling through a clipped direct cable)

[/quote']

NO.. clipped direct.. run where you like taking into account any other relevant external influences

It is concealed cables that safe zones refer to!

Sorry if the questions are stupid' date=' and sorry for so many of them, but they should be nice and easy to help ease you out of your hangover:D.[/quote']

Apology NOT accepted.. ]:)

Questions are no where near stoopid enough! ;) :D

hope that heps m8.
 

moonpig

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Your opinion is worth a lot mate and that helped a lot:D. In fact you have been so helpful i am going to have to think up some more questions for you.

Your like a walking regs book, you bloody handsome bugger:D.

On a sidenote how to go about doing multiple quotes post?

 

Admin1

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Your opinion is worth a lot mate and that helped a lot:D. In fact you have been so helpful i am going to have to think up some more questions for you. :^O

Your like a walking regs book, you bloody handsome bugger:D.

:^O :^O

On a sidenote how to go about doing multiple quotes post?
You can manually add them: (I do)

(] Remove the bold 'Brackets' and you place the text between them that you want to quote and you will end up like the example below.[/quote)]
 

Admin1

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You got it mate. :)

Badger - It not often you are wrong - But you are right, there mate. :^O

 
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