concentric cable ???

[tom79bmth]

Hi all

Just a quick question what is the bs name for concentric cable that the db use for tncs and what size do they usually use on a single house thanks

 

[Richard Burns]

If you have a look at cable manufacturers websites and search for concentric cable they will usually identify the appropriate British standard.
However since cables are covered by a variety of standards such as BEN60228 for the design of conductors for cables and BSEN60811 for test methods for insulation there may not be only one standard applicable.
The one I have just found as being the most commonly referred to is BS7870.

 

[Knobhead]

Think I will just ask at the wholesalers

Why? They won’t supply concentric. Spilt concentric is readily available, concentric is in the realm of the DNO’s.

 

[Guest55]

i think the cheeky monkey OP is craftily planning on using it as a cheap --- sub mains.

you disgust me.



;-D

 

[Knobhead]

If the OP pays me enough I’ll breach joint it in to the supply for him.

BTW Biff 35mm²Al/Cu is the usual now.

 

[VoltzElectrical]

Google is your friend.

So is this forum - supposedly.

 

[Guest55]

BTW Biff 35mm²Al/Cu is the usual now.

not for 100A single phase it isnt.
not unless the nearest mains is 100 or more yards away.

 

[davesparks]

In this area it is always 35mm solid Al core with CU outer conductor for 100A SP

 

[Knobhead]

I borrowed some from down a hole. Definitely 35mmAlCu.

 

[Rockingit]

Around here it's 16mm.

 

[Engineer54]

To be honest, i've only ever seen 35mm concentric being used by the DNO for domestic, small commercial installations. They tend to purchase a one size fits all for these installations, and as stated 35mm aluminium is the going size for a 100A supply... Though looking at the cable dia, it could be easily be excused for looking like a 16mm cable... lol!!

 

[Rockingit]

No, around here, which is WPD, it's definitely 16mm Al with Cu spiral. I've got some, and I've also had to work with it on DNO kit that's transferred to private (don't ask).

 

[Engineer54]

No, around here, which is WPD, it's definitely 16mm Al with Cu spiral. I've got some, and I've also had to work with it on DNO kit that's transferred to private (don't ask).

Well i wouldn't feel happy with a 16mm Ally concentric or split concentric cable with a 100A BS 88 protecting it. A 60A fuse i probably wouldn't be too phased about!! lol!!

 

[Rockingit]

Maybe that's also why they only fit 80A fuses, who knows. They seem to make it up as they go along anyway!!

 

[mechelec]

No, around here, which is WPD, it's definitely 16mm Al with Cu spiral. I've got some, and I've also had to work with it on DNO kit that's transferred to private (don't ask).

WPD standard for single phase TNCS supplies up to 100 A is 25 mm hybrid with aluminium core phase conductor with copper concentric neutrals.

 

[mechelec]

Well i wouldn't feel happy with a 16mm Ally concentric or split concentric cable with a 100A BS 88 protecting it. A 60A fuse i probably wouldn't be too phased about!! lol!!

It could be 400A fuses in the sub station "protecting the cable" The assumption is the service cable will burn open circuit in the event of a fault. Substation fuses do not protect cables they are there to grade with the HV protection for the local TX.