LV and ELV in close proximity.

[ccam108]

I've been having a wee think about the requirement to have LV and ELV cables separated by either 50mm or additional insulation, or both being insulated to highest voltage. (From memory - could someone quote the reg for exact wording?)

Would the outer sheath of a T&E or flex be considered as additional insulation, and is the reg simply referring to single insulated cables, such as conduit singles?

Just something that I've been mulling over for a while, and someone mentioned it in the RCD misconceptions thread so I thought I'd throw it out there.

Comments?

Colin C

 

[holmslaw]

..

 

[bernardgreen]

They must all be rated for the highest voltage present or separated by barriers.

Agree

And they must not be together in a multicore cable unless separated by earthed metal.

Can you quote the source of that ? As I understand it provided the insulation inside the cable is adequate for the voltage difference that may occur in worse case then LV and ELV circuits can be inside the same sheath of cable. Not that there is any benefit for that in the DIY domestic electrical installation.

But, If they are safety circuits they must be completely separate from all other cables and installed in areas of low fire risk.

So do NOT install hard wired fire alarm systems where there is a risk of a fire happening ?

 

[holmslaw]

..

 

[bernardgreen]

Its one of the contradictory conditions of 528.1.

Can you quote the actual text.

] I have given the conditions for safety services in shopping malls and other complex buildings.

Which is not relevant to DIY work in domestic residential properties other than maybe some multi-occupancy converted houses.

 

[holmslaw]

..

 

[bernardgreen]

Read the opening post, I have no idea why he asked the question or what it relates to.

I did. and

(From memory - could someone quote the reg for exact wording?)

was the request.

I cannot read it myself as I am not at the local library, ( I do not have a copy ) and I doubt the OP has a copy otherwise he would not be asking.

As to resistor codes, well I would prefer some of the DIYers who I know to stick with building kits than wiring houses.

 

[holmslaw]

..

 

[ban-all-sheds]

Its one of the contradictory conditions of 528.1.

No it isn't.

I'm not the ops servant, and if you don't like my response, ignore it.

ccam108 - ignore what holmslaw said about multicore cables - he is wrong.

Because I'm not prepared to type out a dozen lines of text from the regs

Because that would show that you are wrong.

 

[ccam108]

OK, can open, worms everywhere...

holmslaw, I'm sorry if asking for someone to quote the reg (I don't own a copy) offended you.

The exact wording of the regulation will probably let me explain better what I'm asking.

The situation I was thinking of was Cat5 or audio sharing a conduit/trunking with power (a very common situation). I can expand if I know exactly what the reg says.


As an aside, on multi-core cables, does that mean that this is illegal?


Colin C