BS7671 Multicore cables.

[topcat72]

Hi There

If anyone can help in pointing me in the right direction within the regs please.

I am a meter engineer and it has been some time since i have had to refer to my regs book since my test and inspection days.
Surveying a meter installation today i have found 2 x 10mm t&e cables serving a 3 phase isolator,
one from the meter which contains 2 no. live conductors with no cpc and the other from a henly block which contains a live and neutral conducor with no cpc.

Regulation 521.8.1 states that "Each part of a circuit shall be arranged such that the conductors are not distributed over different multicore cables"

Is there a regulation that defines this further, i.e each cable single or multicore must contain a neutral or cpc conductor.

Any information would be greatly appreciated.

topcat

 

[davesparks]

you don't have to have a cpc within the cable, like an SWA with seperate CPC is ok. As you have pointed out the situation you have is wrong as you have a circuit split over 2x multicore cables.

But also you have the problem that the insulation of T&E is less than the minimum required for 3 phase 415V

 

[topcat72]

you don't have to have a cpc within the cable, like an SWA with seperate CPC is ok. As you have pointed out the situation you have is wrong as you have a circuit split over 2x multicore cables.

But also you have the problem that the insulation of T&E is less than the minimum required for 3 phase 415V

What about having 2 live conductors within one cable, no neutral or cpc, this will offer no automatic disconnection, only short circuit diconnection if the cable were to be damaged.

my question was really was there a more specific regulation about a multicore 3 phase circuit containing a neutral ?

 

[guest119]

What is the length of these tails TC?

Boydy

 

[topcat72]

What is the length of these tails TC?

Boydy

the 2 x twin and earth cables are only about 1 meter from meter to isolator

 

[davesparks]

What about having 2 live conductors within one cable, no neutral or cpc, this will offer no automatic disconnection, only short circuit diconnection if the cable were to be damaged.

my question was really was there a more specific regulation about a multicore 3 phase circuit containing a neutral ?

The regulation you have quoted is specific! It effectively says that the conductors must be in the same multicore cable and not split up across 2 or more.

You cannot have a regulation which requires a cable to contain a neutral or CPC as it would result in a massive waste of time money and materials in having neutrals in circuits which do not require them.

 

[topcat72]

The regulation you have quoted is specific! It effectively says that the conductors must be in the same multicore cable and not split up across 2 or more.

You cannot have a regulation which requires a cable to contain a neutral or CPC as it would result in a massive waste of time money and materials in having neutrals in circuits which do not require them.

ok thanks, i get that, i just thought there was a regulation that said you had to have a neutral or at least a cpc within any multicore cable single or 3 phase

TC

 

[Knobhead]

If you’re a meter fitter you must have an employer, why aren’t you asking them?

 

[Engineer54]

So what's a Meter Engineer then, cause that's a new one for me??

 

[telectrix]

my local DNO now call their cable jointers engineers.

 

[Engineer54]

I think everyone in the UK seems to be called engineers, from those that repair domestic electrical appliances to gas fitters.... Someone somewhere along the line give them the title of engineer!! First time i've heard of a meter engineer though!! lol!!

 

[7029 dave]

I am an MOP or meter fixer, never heard of that term either. ( am waiting what's MOP) lol

 

[7029 dave]

OP speak to your tech team on the issue.

 

[markc123]

I think everyone in the UK seems to be called engineers, from those that repair domestic electrical appliances to gas fitters.... Someone somewhere along the line give them the title of engineer!! First time i've heard of a meter engineer though!! lol!!

I watched an episode of Watch-dog about 3months ago. It was about a company who repair Hoovers, nothing more, nothing less.

The hidden camera's caught the bloke coming too the house with a younger lad ... the home owner asked some basic questions - are you here to fix the hoover ect... and he introduced himself as the head enginner and the other lad was the apprentice ... apparantly, theirs more too hoover's than meets the eye if it requires apprenterships and head engineers.

 

[telectrix]

i thought a head engineer was a neuro surgeon.