25mm swa armour for cpc | on ElectriciansForums

25mm swa armour for cpc

Post new thread

Discuss 25mm swa armour for cpc in the UK Electrical Forum area at ElectriciansForums.net

R

Rockomuir

-
Joined
Apr 8, 2010
Messages
191
Reaction score
11
Location
South East Kent
Hi all,
Just planning a sub main to an outbuilding .
It will be 80 metre run, buried direct on a 63amp fuse .

So I am thinking of running 25mm swa but just been doing my calcs on whether I can use armour as Cpc. The outbuilding is going to be TT so no need of a bonding conductor on the submain.

After doing calcs in 2 core swa I get
99/51 x16 = 31.02

What I cannot find is csa of 25mm armoured to see if it is big enough .

If anyone could give me the answer it would be most appreciated
 
Rockomuir said:
Sorry I might being completely daft. The swa is going to need a Cpc from the supply end but disconnexted at the outbuilding end as this will become TT. Just wanted to work out if 25mm armoured is big enough to use for cpc
Click to expand...
You mean for if the cable is damaged by say a spade or something and you want to ensure the MCB/fuse blows in the required time? Well I've not done any calculations or anything but I would imagine that they wouldn't make the SWA in long lengths if that was a possibility, that's just common sense to me.

Also I thought problems around the size of the cable armouring only came in to play if 10mm bonding was required. If you are that concerned why not put a time delayed RCD upfront, I'd do that as opposed to up the cable size purely due to cost.
 
Price.
SWA comes in many armour variations, there's aluminium armoured (which isn't SWA in the purest sense), steel armoured and also combination steel armoured with varying numbers of copper armour wires to decrease the armour impedance. You just specify according to your application. If you're creating a TT at the remote end you could also run an external bare copper earthing conductor alongside the SWA cable and connect it to the rod to bolster the TT.

[ElectriciansForums.net] 25mm swa armour for cpc
This is an example of SWA cable with some copper armour strands to reduce impedance if the adibiatic rule isn't met by purely steel strand armour.
 
Last edited:
buzzlightyear said:
Yes you are correct, but lose the armour
Then you are in trouble.
Click to expand...
That could be said for any cables' loss of cpc.
It's unlikely to lose the armour if the gland is fitted properly, Even then, it won't affect the TT end.

I've never seen a damaged/ dug up swa cable with the armour disconnected, leaving the cores intact.
 

Reply to 25mm swa armour for cpc in the UK Electrical Forum area at ElectriciansForums.net

News and Offers from Sponsors

PCBWay
  • Article
Meet PCBWay at electronica A1.163
Join us at electronica 2024 in Munich! Since 1964, electronica has been the premier event for technology enthusiasts and industry professionals...
    • Like
Replies
0
Views
300
PCBWay
PCBWay
Electrical2go
  • Sticky
  • Article
📢 Best Sellers Catalogue Now Available! 📢
Good to know thanks, one can never have enough places to source parts from!
Replies
4
Views
812
Bob Labla
B
Dan
  • Article
The Official Sponsors of ElectriciansForums - There are currently 8
OFFICIAL SPONSORS These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then...
Replies
0
Views
865
Dan
Dan

Similar threads

D
UK Swa as main earth ?!?
You would treat it as a TT installation.
2
Replies
29
Views
1K
westward10
westward10
holmestm
Should the armour of an SWA carrying twin and earth cables also be earthed (with banjos etc)
I assume said contractor is part of a Part P scheme (NICEIC, Napit, few others..) in which case complain to them. They'll investigate (in theory)...
Replies
10
Views
894
Rockingit
Rockingit

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top