Hacked off

[NozSpark]

I went out to see an existing customer this afternoon,,, "could I have a look at connecting up his garage, I've already installed the cable in a duct"

So I'm immediately on edge, thinking what the hell has he done,, is it T&E, flex or joy of joys SWA??

Well the answer is neither of the above:O

He's recently had his service cable replaced & re routed from an over head to under ground (TNC-S) and had a word with the guys doing the job,,,, they left him an end of reel saying "that will do the job, no problem" and as they are the suppliers "experts" he beleives them...

They've given him 25mm solid core (aluminium) straight concentric

No matter what I told him he wouldn't beleive that this cable is not suitable,,, when I said that I would not do it he said that there are plenty of other electricians locally and he's sure that someone will hook it up:red card

 

[Andy™]

or more likely, he'll end up connecting it when no-one else will

 

[ProDave]

Tell him to pull it out and take it to the scrap dealer, then buy some SWA or split concentric.

 

[revjames]

no offence but jointers arent the cleverest of DNO workers

 

[safedepth]

Noz, at the risk of sounding daft, what are the reasons for not using it?

I have the following theories but have never seen let alone touched solid core straight concentric,

25mm Solid core will be totally inflexible when trying to terminate, and is there an issue with it being ali. Without getting the BGB out I'm sure it has lower conductivity but 25mm must be good for a few amps!

 

[steptoe]

Where are you going to get your cpc from safedepth?

Thats just for starters.

 

[Andy™]

straight con has no earth, and the outer is neutral and not adequately insualted to 7671 (neutral is sheathed, not insulated)

no problem with split con (separate neutral &earth, and neutral is insulated/sheathed)

 

[sellers]

edit * noobed out

 

[NozSpark]

1 as far as I'm aware it's not a recognised cable type in BS7671

2 it's only a 2 core cable so you can have L & E or L & N,,,, not L, N & E.... You could combine N & E, but that's not allowed in the regs either!

3 how would you terminate it?

There are probably more reasons, but I can't think of any right now

 

[safedepth]

Thanks you 3.

Steps, I see what you mean but Like Sellers I'm a little surprised you have even entertained the idea of exporting.

I will have to track down some pictures of this stuff.

Thanks again, especially for being gentle.

And you Noz, we were typing together.

 

[Andy™]

Thanks you 3.Steps, I see what you mean but Like Sellers I'm a little surprised you have even entertained the idea of exporting.

I will have to track down some pictures of this stuff.

Thanks again, especially for being gentle.

And you Noz, we were typing together.

even if you dont export the earth and TT the outbuilding, the cable still does not comply with 7671

 

[apprentice87]

Hi all,

Now, i am no expert!! But first off, i would think it was WELL against the regs for the following reasons;

1, All cables buried in the ground, unless they are in a duct "which provides equivalent protection against mechanical damage" to quote the regs, "shall incorporate an earthed armour or metallic sheath or both" to quote the regs again.

If you used this stuff, then the only way you could do it, is to use the "TNC" earth and neutral combined, [same as the supply to the house in the first place, BEFORE they were separated at the cutout, and "converted" to TNC-S] cos if you just used the concentric part purely as a neutral, the "armour" if you like, would not be earthed.

Now, you ABSOLUTELY CANNOT do this as you are not allowed to have TNC earthing systems in your "private" [as in not DNO] installations. Sooooo, that idea is right out the window!!!

Next one; Say then, you DID have it in a suitable duct and were going to TT the garage [so you could just use the cable as a concentric cable [no earth, just phase and neutral] then how you going to "make it off" ?? what sort of glands you going to use??

The "outer" concentric part, is only thin copper wires. It is like big telly co-ax, only not braided. The DNO do not use glands, they just terminate the aluminium core, and twist the copper strands together, wrap tape round them, and stuff them in the neutral block...

All this cable is, is scrap....

john..

---------- Post Auto-Merged at 20:14 ---------- Previous post was made at 20:11 ----------

Ha ha, you all beat me to it!!! teach me for being slow typing!!!!

john..

 

[Sidewinder]

john,

1 other thing the live conductors are not adequately insulated as the outer, in your ducted case, the N is only sheathed not insulated as it must be.

 

[apprentice87]

Hi Paul,

See what you mean, as in its INTENDED use, it could be argued that the outer is not, i suppose, a "live" conductor [in the way that a neutral is] as it doubles as earth too!!!

Thanks

john..

 

[steptoe]

John, DNO have their own rules and 7671 is not something they have to worry about.

therefore the insulated and sheathed issue doesnt come into play for the cable in its intended use.

 

[choccy]

Had a situation the same when i went recently to price up connecting a power and lighting supply to a new metal shed. No rcd in the property either.

So proceeded to price for cable, rcd, garage 2 way fuse board, earth rod, boxes ect. Gave price off

 

[steptoe]

Thanks you 3.Steps, I see what you mean but Like Sellers I'm a little surprised you have even entertained the idea of exporting.

I will have to track down some pictures of this stuff.

Thanks again, especially for being gentle.

And you Noz, we were typing together.

even without exporting you still require a cpc to protect the outgoing cable,

so there,

na na na naaa naa

 

[kerching]

Well, I use my mate's barn as a sort of 'off-site seldom-needed bulk-materials store'. He was having the floor concreted and I told him he needed to get a duct in so that we could run a cable to his future bench saw. No problem, or so I thought! Yes he did put a duct in; a bit of the red UU stuff. He also "helped me" by putting some cable into said duct, stuff of mine that was lying about.

So do you know what I 'got'

1 x 20pr CW1308 BT cable

1 x 50mm tri-rated singles

He obviously knows something that I don't!!.................. :coat

 

[NozSpark]

Oh I do like that Kerch ROTFWL :slap

 

[Terry W]

he said that there are plenty of other electricians locally and he's sure that someone will hook it up:red card

I'll do it, just ask him to sign my std disclaimer

I instruct you to connect my outbuilding using the unsuitable cable I have got cheap from some bloke working at the house, the unsuitable cable has been installed by myself / others to no know standard. I have no interest in electrical safety & should any persons / livestock be injured or property damaged I have no objection to being held financially liable or spending time in on E wing as I enjoy showering with other men. I