Terminating SWA at plastic Comsumer Unit

[Voltimax]

Well BS 7870 does not appear in appendix 1 of BS 7671.

Also I had a chat with NAPIT technical about it and as I stated previously, their stance is that they recommend it is not used. I'm referring to both cables, so there is no confusion.

When looking up BS 7870 it states:

LV and MV polymeric insulated cables for use by distribution and generation utilities.

 

[batty]

I thought concentric cables where only used by dno. I personally have never used it only time I have come across it was on a recent job at some stables where a long bit had been used between meter and stables not a good idea as the cable had no cpc. As for using stuffing glands on consumer units why not. If it is pme and you use a standard swa gland you are not going to be able isolate house earth from shed or outbuilding earth. I always TT outbuildings that is why I use a nylon gland that way the house earth is seperate to the shed earth.

Batty

 

[Andy™]

I thought concentric cables where only used by dno. I personally have never used it only time I have come across it was on a recent job at some stables where a long bit had been used between meter and stables not a good idea as the cable had no cpc. As for using stuffing glands on consumer units why not. If it is pme and you use a standard swa gland you are not going to be able isolate house earth from shed or outbuilding earth. I always TT outbuildings that is why I use a nylon gland that way the house earth is seperate to the shed earth.Batty

your getting a bit mixed up... there are 2 types of concentric cable - straight and split - straight con has a centre core and all uninsulated outer cores and is only used by DNO for TT or PME supplies. Split con has a centre core, half outer cores are insulated for neutral, and half uninsulated for earth - can be used as a submain, or you could even use it instead of T&E. can also be sued by DNO for TN-S supplies

 

[Voltimax]

andyc,

Are you deliberately ignoring my replies to this thread?

Google BS 7870

LV and MV polymeric insulated cables for use by distribution and generation utilities.

Correct me if I am wrong, or preferably point me in the direction where it states it's suitability to be used by consumers as it has no reference in BS 7671.

The links that have been posted by 0151 do not even mention which parts of BS 7870 the cable complies with.

Not looking for a fight, rather some clarification

 

[batty]

your getting a bit mixed up... there are 2 types of concentric cable - straight and split - straight con has a centre core and all uninsulated outer cores and is only used by DNO for TT or PME supplies. Split con has a centre core, half outer cores are insulated for neutral, and half uninsulated for earth - can be used as a submain, or you could even use it instead of T&E. can also be sued by DNO for TN-S supplies

So is it cheaper than standard swa because unless it is I can see no other reason for using it.

Batty

 

[Andy™]

So is it cheaper than standard swa because unless it is I can see no other reason for using it.Batty

not always cheaper, but easier to work with so time savings can be more than additional cost

 

[Andy™]

andyc,Are you deliberately ignoring my replies to this thread?

Google BS 7870

LV and MV polymeric insulated cables for use by distribution and generation utilities.

Correct me if I am wrong, or preferably point me in the direction where it states it's suitability to be used by consumers as it has no reference in BS 7671.

The links that have been posted by 0151 do not even mention which parts of BS 7870 the cable complies with.

Not looking for a fight, rather some clarification

sorry - didnt see first post and kinda forgot about other post when i replied earlier!

I first used the stuff working for a council. now working for myself, i have also used it a few times (when i can get hold of it!). i dont think BS7671:2008 specifically includes it, but it does state somewhere other BS stuff may be used - providing safety isnt compromised etc. under now under 17th, it cannot be used the same as SWA because it isnt earthed all round - part of it is neutral. so it has to be treated like T&E. for submains, in certain conditions, you could use T&E, but good luck finding 25/35mm T&E (and without needing a second earth). so your down to seperate tails & earth, SWA or split con. since split con is easier to use, and diameter is smaller againt same sized SWA, it can be a better choice.

Also, DNO mostly use it because its much easier to work with than other cables - termination times are cut compared to SWA, so they are saving loads on labour

kinda similar situation to BS8436 cable - IIRC, this was never mentioned in 7671:2001/4, but it was around and could be used (altho it was almost unheard of till 7671:2008)

And final note, BS 7870 is as you mention. BUT, there is also BS 4553 - Specification for 600/1000 V single-phase split concentric electric cables. Cables having PVC insulation

 

[Andy™]

Where do you find the tables for volt drop, technical data etc?

i have contacted Cleveland Cables in the past - they basically said treat as SWA for technical info - and many other i have spoke to all say the same. altho if you do get through to someone at a cable co who is useful, they may be able to get the full technical info for you