swa

[switched on]

I've always used a 3 core armoured so it has its own internal earth. I always earth up the armoured to use the steel wire with a gland and banjo but i worry that if i don't use a 3 core and just a two core and the steel armoured as the earth is this ok?
Obviously safety is the key feature but when can you use the steel and just run a two core?? Just a funny subject i feel. Thanks alot

 

[martysparky]

How many times do you hear the expression 'Drove a rod in for good measure'.


Is there any reason why the armour should not be earthed both ends?

apart from what has already been stated

 

[pushrod]

Is there any reason why the armour should not be earthed both ends?

If you are exporting an earth with 2 core SWA there would be nothing to attach it to at the earth rod end.

 

[kevben]

I've got quite a few submains to install soon (25mm 3 core SWA) and have always glanded and banjo'd at both ends. I usually terminate the gland through a metal adaptable box before entering CU.This is unsightly and usually means the builder needs to build a cupboard to conceal equiptment.

Can i just tape up the armouring at the CU without glanding as it would be bonded at the Origin of the supply through a Switch Fuse (100A) ?
If NOT can i install adaptable box with gland termination inside a stud wall ,behind CU,(wouldn't be accessible after plastering)?
Would make my life a lot easier if there is no problem with either question.

 

[martysparky]

Connections & Terminations

Connections must not be subject to any mechanical stress or strain. 526.6, 530.4.1
All screw connections must be accessible. 526.3 Through crimp connections do not have to be accessible. 526.3
Stranded cable ends must be fitted with appropriate terminals or suitably treated. 526.8.1
Every termination, connection or joint between live conductors including the neutral conductor must be made in a suitable accessory or enclosure. 421.7, 526.5

 

[kevben]

Thanks Marty, Not sure if that has answered my questions. I guess what you are saying is that option 2 would be ok , as i was proposing to just terminate the gland into the metal box and install the cores into the CU through the back with No joints.

 

[pushrod]

Marty, in reponse to an earlier question about earthing both ends of the swa have a read thru reg 542.1.8. Basically, if there are separate earthing arrangements the cpc must be able to carry the max fault current or be earthed at only the end with the protective device.