Sub Main

[sparky999]

Evening all.

Just started a new build today the size of the property is 55000sq feet pretty big, so we will be putting in a sub board in splitting it roughley in half.

In total for the half the sub board is goin there will be around 100 downlights up and down being on 4 6a cb and 50 sockets up and down with that being on 2 32a cb.

My boss has told me we will run a 16mm t&e and a 10mm earth in as well, the length of the run is approx 20 metres back to the 1st ccu.

So is 16mm suitable?

Thanks very much

 

[green-hornet]

I would rather not run 16mm t&e would prefer 16mm swa no need for the extra 10mm earth then.

Total maximum demand for the breakers you are putting in with diversity would be 37amp

(add all used breakers together and multiply by 0.42) Round up if you get .***

16mm swa would also be about

 

[Andy™]

whats the chance of it needing more power in the future? maybe 25mm SWA just in case?

and dont forget your volt drop includes submain and final circuit, so the less you have on submain, the more you can have to the final circuit

 

[M107]

I'd go swa as GH says, you could go 2 core & use the armour as cpc (from memory the armour is equivilant to 50mm )

 

[green-hornet]

Armour csa

1.5mm = 17

2.5mm = 20

4.0mm = 22

6.0mm = 36

10mm = 42

16mm = 50

25mm = 70

35mm = 78

And if you use the big stuff

50mm=90

70mm=131

95mm=147

120mm=206

And if your strong enough

150mm=230

185mm=255

240mm=289

300mm=319

400mm=452

Two core with armour as cpc no need for discrimination of downside rcd and an equivelent og 50mm cpc cant go wrong! (unless you gland it wrong of course)

 

[SPECIAL LOCATION]

Armour csa1.5mm = 17

2.5mm = 20

4.0mm = 22

6.0mm = 36

10mm = 42

16mm = 50

25mm = 70

35mm = 78

And if you use the big stuff

Applaud Smiley:^O:^O:^O:^O

50mm=90

70mm=131

95mm=147

120mm=206

And if your strong enough

:^O:^O

150mm=230

185mm=255

240mm=289

300mm=319

400mm=452

Two core with armour as cpc no need for discrimination of downside rcd and an equivelent og 50mm cpc cant go wrong! (unless you gland it wrong of course)

Nice post ther GH! :x

 

[green-hornet]

Thanks specs, you would need some big bicepts for the big stuff, I bought a hydrolic crimper for 300mm earth lugs used it once, should have gone to hire it.

 

[bob]

use 400mm just to be safe

better to be safe than sorry

bob

 

[0151]

run a 25mm split concentric cable.

overall diameter is smaller than swa also can be made off easier just like t&e

I called pirelli many moons ago and the earth part is 16mm.

 

[Andy™]

 

[batty]

I am a little confused with those figures in the tables. The uneeda publication I have although it is 16th edition states that a 16mm swa three core armour is equivelent to 4mm copper and cannnot be used for pme connections. If this is a new build surely it will be pme or am I barking up the wrong tree here.

Batty

 

[Apache]

I am a little confused with those figures in the tables. The uneeda publication I have although it is 16th edition states that a 16mm swa three core armour is equivelent to 4mm copper and cannnot be used for pme connections. If this is a new build surely it will be pme or am I barking up the wrong tree here.Batty

Batty posted a link to here a while back

 

[batty]

Batty posted a link to here a while back

You are quick finding these links Paddy.

 

[Apache]

You are quick finding these links Paddy.

Blushing

I found your origional link but it's broken so I found the site and re-linked

 

[batty]

BlushingI found your origional link but it's broken so I found the site and re-linked

I would like to know who broke it . We will have to send the dons boys round.

Batty

:coat

 

[green-hornet]

The use of internal cores, of both thermoplastic and thermosetting SWA cables, as a CPC and/or the use of separate parallel CPCs are not required for SWA cables to comply with BS7671 provided.

1.The operating temperature of the cable does not exceed 70

 

[Apache]

I would like to know who broke it . We will have to send the dons boys round.Batty

:coat

it's your post - you could edit it?

 

[Andy™]

The use of internal cores, of both thermoplastic and thermosetting SWA cables, as a CPC and/or the use of separate parallel CPCs are not required for SWA cables to comply with BS7671 provided.1.The operating temperature of the cable does not exceed 700C.

were using pyro rated SWA these days?!

 

[green-hornet]

That does appear to be a little high!!

 

[Apache]

That does appear to be a little high!!

If you type in word and use superscript to make a 0 look like a degrees sign the forum removes the formatting and it looks like 700 rather than 70