4 core swa feeding ring

[sibbits]

just wondering what other people think of wiring leg out to a ring in a single swa 4core 2.5 using the armoring as the earth?
its about 10 mtrs from the board and wouldnt have massive loading on the end.
i know that using 2 seperate pieces is best but i have a piece of 4 core long enough and am thinking bout using it .

 

[telectrix]

use 2 cores for each leg.

 

[Knobhead]

Just had a look in the tables I have, can't see a problem of using the armour as CPC. As Tel said keep the two legs seperate.

 

[Silly Sausage]

If this is domestic, I wonder how he's going to terminate the ends?

 

[sibbits]

If this is domestic, I wonder how he's going to terminate the ends?

nope its a commercial install for some wash tanks . i have got some 4core left over from a fan install and was trying to use it up.

 

[telectrix]

be sure to gland and fly lead it if you're using the armour as cpc.

 

[sibbits]

nah .....i was gonna put it thru a rubber blank and use a bonding clamp attached to the armouring:biggrin5:

 

[telectrix]

you may laugh, but seen that done several times.

 

[Darkwood]

Just a little cautionary thought - your L or N ring will be 20m long ring but your armour only 10m assuming you are having a 32amp front end then your csa of the armour may not be sufficient enough to ensure you meet your ELI requirements as you have effectively taken half the earth ring away and left a radial earth.

 

[sibbits]

what ?thats not up to standards?*blushes*
ok ill do it the right way.

 

[sibbits]

i though it would probably affect the loop value .this is why i have posted . ill just order some better cable and save it for something else. i

 

[telectrix]

he said "may not be sufficient". time to do some calculations.

 

[uksparks]

I was just thinking, if you use this, how are you going to get your r2 ring value? as it will be one piece at the SWA...

 

[Silly Sausage]

I was just thinking, if you use this, how are you going to get your r2 ring value? as it will be one piece at the SWA...

What would you do with an RFC with metallic containment as the CPC?

 

[Pete999]

Unless you have two socket close together it will be a bit messy connecting it as a RFC

 

[uksparks]

What would you do with an RFC with metallic containment as the CPC?

You would only be able to get an R2 reading as its not a ring. I am aware of this, its just the person was looking at extending both legs but just using one conductor / armouring for CPC instead of having two that's all.

 

[Knobhead]

4 core SWA amour = 20mm² whereas the minimum requirement is 5.7mm² (single circuit) for steel wire.

Where’s the problem if the SWA is terminated properly?

 

[Knobhead]

I was just thinking, if you use this, how are you going to get your r2 ring value? as it will be one piece at the SWA...

How would you test a lollipop ring? The proposed set up isn’t out of the ordinary for experienced electricians.

 

[Darkwood]

4 core SWA amour = 20mm² whereas the minimum requirement is 5.7mm² (single circuit) for steel wire.

Where’s the problem if the SWA is terminated properly?

Spoiling my fun Tony - trying to get him to think like an Electrician if he checked it he'd realise it was well within tolerances with spare.. but being told yes its ok won't get him to realise why its ok... but as he never counted my post with yes it works out fine i assume he didn't bother checking.

Ive stopped giving out straight answers now im getting the OP's to contribute to solving their issues more and understand the calcs behind it as it seems less and less now bother with them as scary as it sounds.

 

[Silly Sausage]

Ive stopped giving out straight answers now im getting the OP's to contribute to solving their issues more and understand the problem better and hopefully never forget

I stopped dishing it out a long time back, just give hints or another question.
Make the buggers think!