Mr S.Parks

Morning all.

Doing a job just now which will involve terminating swa in the mains(8 properties)

It's 25mm 3 core swa and domestic mains.

It would be nice if it could be hidden in the partician instead of surface mounting and entering via the incomer knockout.

All I can think of is making the end of and using a earth clamp(as used for earth bonding) for the wire armour, connecting an earth to the clamp and bringing all cables in via rear cable entry on the mains.

Does anyone have a better way or experience terminating something similar? 

Thanks

Use of a BS951 clamp in this scenario would be outside of the scope of BS951 & the manufacturers instructions for the clamp.

You would need to note this down as a deviation on the electrical installation certificate for the jobs.

If you are terminating this into the consumer unit, this will be a metal enclosure so you can utilise an SWA gland.

If this is at the supplier end, then the armour must be connected to the supply earth, the bedding (the stuff between the armour and the cores) is not considered adequate mechanical protection outside an enclosure, and any exposed basic insulation would be a total non-compliance with BS 7671.

So termination of the armour at the cut out end would need to be via an adequate gland, into a suitable enclosure, and then from there in perhaps "meter tails" that is insulated and sheathed singles, to the meter etc.

Now depending on the IP rating that is required for the enclosure, it is unlikely I suspect that it would need any significant IP rating, a metal adaptable box enclosing some "Henley" blocks or a terminal rail with terminals could be suitable.  Personally I would prefer not to see "floating" strip connectors.

I guess you are OK "hiding " the SWA in a partition  without an RCD  , as the SWA  is an earthed sleeve .  

mechanically protected is the phrase.

You cannot use an earth clamp for the armour. Can you mot use swa gland into metal CU? failing that terminate cable to a box then enter the CU

Thanku all for your thoughts and time esp sidewinder- nicely explained.

Excuse my ignorance but, can I make the swa gland of behind the mains and within the partitian if said partition is considered an enclosure? Perhaps stick a swa gland on(not connected to earth but just to tidy the armour up). Then bring the 3 cores in via rear entry and terminate?

Mr S Parks said:

Thanku all for your thoughts and time esp sidewinder- nicely explained.

Excuse my ignorance but, can I make the swa gland of behind the mains and within the partitian if said partition is considered an enclosure? Perhaps stick a swa gland on(not connected to earth but just to tidy the armour up). Then bring the 3 cores in via rear entry and terminate?

Click to expand...

I would say no .... the gland should be visible for inspection ....

Then if no gland used at mains end and if partition acts as a enclosure(for the prepared mains rear cable entry) then do u think it would be compliant with bs 7671?  The swa being glanded/earth at cable head.

Mr S Parks said:

Then if no gland used at mains end and if partition acts as a enclosure(for the prepared mains rear cable entry) then do u think it would be compliant with bs 7671?  The swa being glanded/earth at cable head.

Click to expand...

Imho no .....

Then if no gland used at mains end and if partition acts as a enclosure(for the prepared mains rear cable entry) then do u think it would be compliant with bs 7671?  The swa being glanded/earth at cable head.

Thank you for your time Murdoch but if you or any other learned collegues have any ideas for keeping the swa mains cable  tidy I'd be most greatful

An SWA cable requires a gland to comply with its product standard, to use without is a deviation, and must be as safe or safer than compliance.

This can't be the case in this scenario.

I am getting a bit confused with the terms you are using.

When you say mains are you referring to the supply end of the cable?

Sorry sidewinder.

Swa Glanded/earthed at meter end(Bronco type cupboard) with the idea of bringing the swa in through the rear of the cu and then terminating it. Instead of the swa being brought out of the partician and glanded into the side of the cu.

Purely just to hide the big black cable

Thought I'd sent this last night. Me learning to use this site on my phone

OK, I have no idea what you mean by a Bronco cupboard, but that doesn't matter.

As long as the SWA is correctly glanded and terminated at the supply end.

As far as the load end goes, if you do not gland the cable off, how are you going to comply with MI's, & BS 7671 clauses 134.1.1, 421.1.1,  510.3, 522.8.5 & 530.4.1?

Bearing in mind that the SWA cable standards also require glands to be fitted to the cable.

As I see it there are a number of issues with what you propose, aside from the non-compliances with various regs as already pointed out, there are also a couple of other issues. Number one, if you attach the armoured to a set of tails inside the partition wall, you are going to use Henley blocks or something similar, now as these are not designated maintenance free, then they need to be accessible in order for them to be able to be checked for correct tightness.

Number two, at some point this installation is going to require inspecting, now I can't speak for others on here, but, If I were carrying out the inspection then seeing a set of tails going into the CU I'd want to know where they change from tails to whatever cable is feeding them from the origin of the installation ( distributors intake position), Without seeing how and where this change occurred then I'd be reluctant to sign the installation off as safe, and I'm sure most other responsible electricians would agree with me on this.

While I can appreciate that you are trying to make the installation appear neat and tidy, I feel  this is definitely a case of 'form over function', and regardless of how much of a desire you have to make the install appear neat, this CANNOT be at the cost of not only compliance with the regulations but more importantly safety.

Why not just put the SWA Into a bit f 100 x 50 plastic trunking and run it straight up to the board?

just staying

There is a way to terminate a SWA with no gland but it needs a lot of heat shrink tubing and a break out boot. The supply end needs a gland to earth the armouring.

Gez, thank u all for all the thought provoking info..

Curious about the breakout boot. Would that comply with the manufacturers instructions and would the cable end(one with the boot on) require access for inspection?

Mr S Parks said:

Gez, thank u all for all the thought provoking info..

Curious about the breakout boot. Would that comply with the manufacturers instructions and would the cable end(one with the boot on) require access for inspection?

Click to expand...

With a breakout boot you wouldn't actually gland the armoured at the CU end, just at the intake end, you'd strip it back about 2 feet, as though you were making it off into a gland, but instead of attaching a gland you place a piece of heatshrink tube over the sheath to cover the armouring and sheath, then shrink this down. Next you attach the breakout boot, this is a bit like a glove with three fingers, the 3 cores go through the 'finger holes and this slides over the piece of heatshrink you applied earlier and is shrunk down, next more heatshrink is applied ofer each individual core to provide the double insulation, again this is slid down over the 'fingers' before shrinking down, finally the cores are taken into the board using a normal tails gland in the same way you'd do it if you were using ordinary tails.

These kits are not cheap and to be honest would be a bit of an un-necessary thing for the situation you describe, personally I'd just use a normal gland and get it done.

https://www.cablecraft.co.uk/heatshrink-3c-breakout-boot-3.html

Ta for taking the time with the info Phil d.

Sorry for my slow reply but life got a bit busy.

Needing more experience with compliance but does ur method comply with mfs instruction or just require a note as a deviation?

Speaking personally ,  I wouldn't worry about the SWA being on show  ,  others make the  Regs  not us ,  just gland it into the  board .  It'll be as pretty as the gas meter  pipes  .