16mm T&E for external building

[westie101]

I still wonder whether the sheathing is not perhaps more UV-resistant than you seem to believe.

I have no worry about the cable as I've seen it used outdoors for many years and, as I've said, am sure it is the same PVC as used in meter tails & T & E.

I think it is more that outside the ESI there is a huge fear of using it outdoors which I see as unnecessary.

 

[JohnW2]

I still wonder whether the sheathing is not perhaps more UV-resistant than you seem to believe.

I have no worry about the cable as I've seen it used outdoors for many years and, as I've said, am sure it is the same PVC as used in meter tails & T & E.

... and, as I've said, I don't doubt that. However, as I've also said, I'm not convinced that the PVC sheath in such cables is the same (UV-resistance wise) as that of standard grey/white-sheathed T&E - which is what we were talking about.

I think it is more that outside the ESI there is a huge fear of using it outdoors which I see as unnecessary.

As I have implied, I essentially agree, even for T&E.

Kind Regards, John

 

[influx]

16mm 2 core SWA is about £3.60 a metre, you aren't going to save much money messing around with T&e or tails in conduit, plastic pipe or clipped exposed.

Indeed. Actually, per current TLC prices (excl VAT) 16mm² 2-core SWA is £4.15 per metres, as compared with £3.91 for 16mm² T&E - a difference of 24p (28.8p incl VAT) per metre. Hence, by the time one has bought conduit (or whatever), using T&E would almost certainly be more expensive. Admittedly, one would also have to buy glands for the SWA (a few pounds) - and some would favour 3-core SWA (£5.64/m excl VAT, £6.77 incl VAT).

Interestingly, if he used 10mm², at TLC prices T&E is much more expensive than 2-core SWA!

Whatever, I really do not see how the OP can perceive a significant enough cost difference to persuade him not to use SWA.

Kind Regards, John

I was working on £2.68/m (inc vat) which was the cheapest 16mm2 T&E i found online so over 25 metres its not an insignificant cost.

 

[JohnW2]

I was working on £2.68/m (inc vat) which was the cheapest 16mm2 T&E i found online so over 25 metres its not an insignificant cost.

Is that "cheapest you could find on-line" a reputable make from a reputable source (rather than an anonymous make from eBay)? There have been recent problems with substandard (unsafe) batches of cables, which are costing retailers and wholesalers fortunes.

Kind Regards, John

 

[ban-all-sheds]

I was working on £2.68/m (inc vat) which was the cheapest 16mm2 T&E i found online

And the cheapest 2-core 16mm² SWA I found online (with a very quick search, so I'm not claiming it's the cheapest out there) was £2.90.

so over 25 metres its not an insignificant cost.

£5.50. If that's significant you shouldn't be doing this project at all.

I would seriously counsel against buying the cheapest cable you can find. As more manufacturers and suppliers join in the race for the bottom there are an increasing number of dodgy cables coming onto the market. Even large retailers and their customers are not immune.

http://edmundson-electrical.voltili...s-woolworths-australia-big-financial-headache

You're not tendering for the wiring of Crossrail where a few quid per roll is a major concern.

Shop around, yes, but stick to known reputable brands like Pirelli, Prysimian, Nexans, BATT, BICC etc.

 

[influx]

I was working on £2.68/m (inc vat) which was the cheapest 16mm2 T&E i found online

And the cheapest 2-core 16mm² SWA I found online (with a very quick search, so I'm not claiming it's the cheapest out there) was £2.90.

so over 25 metres its not an insignificant cost.

£5.50. If that's significant you shouldn't be doing this project at all.

I would seriously counsel against buying the cheapest cable you can find. As more manufacturers and suppliers join in the race for the bottom there are an increasing number of dodgy cables coming onto the market. Even large retailers and their customers are not immune.

http://edmundson-electrical.voltili...s-woolworths-australia-big-financial-headache

You're not tendering for the wiring of Crossrail where a few quid per roll is a major concern.

Shop around, yes, but stick to known reputable brands like Pirelli, Prysimian, Nexans, BATT, BICC etc.

Where did you see it for £2.90? I've been looking at 3-core though as i assumed it would need an earth. I've put the pricing i've seen below and it comes out quite a bit higher.
Im not saying i'll quibble over £27.50 though, i just don't want to throw money away if its not necessary.

I was pricing from shop4electrical.. unsure if they are good or bad?

6943X16.0MM BASEC Approved 6943X Black 3 Core Steel Wire Armoured Cable 16mm - £3.33
6242H16.0GRY1 BASEC Approved 6242Y Grey Twin & Earth Cable 16mm (priced per metre) - £2.23

Difference £27.50

 

[EFLImpudence]

Plus vat.


I'm still puzzled.

Could someone please explain why, with even the most onerous bonding requirements, larger than 10mm² would be required?
Swa £2.27 + vat.

 

[RF Lighting]

It all depends on whether you need to take a bonding conductor to the outhouse as mentioned earlier.

If you do, T&E will certainly not be suitable. 2 core SWA may not be suitable, but would need some calculations to determine this.

3 core SWA will be good for all eventualities.

Bonding conductors need to be a minimum of 10mm² and the maximum resistance allowed for a bonding conductor is 0.05Ω

10mm² will be ok if the run is short enough.

 

[ban-all-sheds]

Where did you see it for £2.90?

http://www.csecables.com/acatalog/SWA_.html

I've been looking at 3-core though as i assumed it would need an earth.

It will.

What do you think the armour does?

Difference £27.50

Trivial.

Less than the price of a takeaway curry for two.

If £27.50 is so significant that you would avoid using the right cable to save it then you should not be doing this project at all.

 

[JohnW2]

I'm still puzzled. ... Could someone please explain why, with even the most onerous bonding requirements, larger than 10mm² would be required?

This arose in relation to T+E. 10mm² T+E has a 4mm² CPC - not enough for any main bonding.

Kind Regards, John

 

[ban-all-sheds]

And 16mm² T&E has a cpc of just over 5mm², so ditto.

 

[EFLImpudence]

It all depends on whether you need to take a bonding conductor to the outhouse as mentioned earlier.
If you do, T&E will certainly not be suitable. 2 core SWA may not be suitable, but would need some calculations to determine this.
3 core SWA will be good for all eventualities.

I realise T+E is unsuitable and it should be swa anyway.
The OP is quoting for 3core swa.

Bonding conductors need to be a minimum of 10mm²

I realise that.

and the maximum resistance allowed for a bonding conductor is 0.05Ω

That is not so.

10mm² will be ok if the run is short enough.

Is there a regulation stating a maximum resistance and therefore length?

 

[Lectrician]

The regs state 0.05 ohm.

Split concentric is table 54.7 compliant, 16mm axing a 10mm earth.

SWA preferred, but glanding at the house end could be awkward.

Split con at 3m high, cleated to a wall? No issues.

 

[JohnW2]

And 16mm² T&E has a cpc of just over 5mm², so ditto.

"just over 5mm²" ?? I thought it was 6mm² - is that what you meant?

Kind Regards, John

 

[skotl]

LOL. Blooody auto correct.

What autocorrect provision are you using which doesn't allow you to review the "corrections" it's made before you post?

You could start an argument in a monastery, b-a-s