help needed

[bisto3010]

I've been domestic bashing for the last 5 yearsworking on extension and minor rewires which has suitedmy purposes, I've recently taken a job with a reputable electricalcontractor and as a baptism by fire I've got 10 CU's to feed with amixture of 6mm & 10mm (3 Core) SWA. In all cases the SWA terminatesexternally to plastic IP56 boxes mounted on metal containers (with appropriate20/25mm SWA glands). In 3 out of the 10 ofthe CU’s there is in excess of 2 meters from the entry point. I’ve alwaysworked on the principle that the all SWA needs to be terminated within 1m ofthe entry point and all cores extended using Henly blocks etc, however I’m notsure if this is regulation (and I’ve looked and can’t find the answer) or justsome fable I’ve picked up. I would liketo terminate the SWA to the plastic JB, obviously maintain continuity of CPC/Earthusing the banjo’s and a 10mm earth fly, but is it permissible to then bring inthe SWA cores to the CU’s which could exceed 2.5m.
The jobs well paid and I don’t want to look a newbe onsite, all advice welcome.

 

[telectrix]

fcrom what you say, it appears that you want to gland the SWA then continue the cores as tails to the CU. no way, unless those cores are enclosed as they are not sheathed/double insulated.

 

[Plonker 3]

Do you mean the SWA terminates into a suitable enclosure then continues externaly with them cores insulated and inner sheather external to the IP65 box?

 

[Engineer54]

fcrom what you say, it appears that you want to gland the SWA then continue the cores as tails to the CU. no way, unless those cores are enclosed as they are not sheathed/double insulated.

As Tel states. There is one way around this and that's applying a suitable heat shrink tubing to the exposed tails, preferably adhesive lined heatshrink. But the system as you describe, sounds a bit cac to me...

 

[guest119]

Double lockring your banjo if using a plastic box.
One to lock the banjo to the gland and one to hold it all to the box.

 

[Gazzdid]

Bisto i think you need to be more clear on info. Are you terminating the swa and then continuing the cores into the db's via suitable containment i.e trunking etc? The way i read it i think your just worried about the terminations being 2M away from where the armoured is glanded which i cant see a problem with as long as its suitably enclosed.
Are you thinking about domestic incoming tails from meter to db needing to be <2M?

 

[telectrix]

Double lockring your banjo if using a plastic box.
One to lock the banjo to the gland and one to hold it all to the box.

or use pirhana nuts (or similar). generically called earthing nuts. these have a locking grub screw. very rare i'll use banjos since first using them.

 

[bisto3010]

Hi Gazzdid, yes the SWA will be terminated to an external plastic box (suitably earthed), the 3 core tails then taken to the DB which is approximately 2.5m from the entry point in eclosed in plastic trunking.

 

[bisto3010]

it's standard 6mm or 10mm 3 core SWA, all cores are initially PVC insulated and then a further PVC flexible sheath encasing them, so I don't think double insulation is an issue. The cores will be taken to the DB's enclosed in plastic trunking.

 

[bisto3010]

I've not seen pirhana nuts before, I'll get hold of a couple and see how I get on with them, many thanks

 

[bisto3010]

no swa terminates to a plastic IP56 box, then cores will continue internally enclosed in plastic trunking

 

[Engineer54]

So only the SWA has been terminated at the plastic box and the inner sheath carrying the 3 cores are then taken away via PVC trunking, Nothing much wrong with that. If only you explained that in the Threads OP!!

 

[Had8Lives]

Seems odd to use trunking if the SWA is long enough to reach the Consumer Unit.