Underground cable joints (IP rating)

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wotnoearth

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Here goes my first real post!?!

I have been asked to install 7 x 230v post type garden lighting bollards. My intention is to swa feed to joint boxes and come off those with HO7 RNF (heavy duty) type flex to the bollards.

My question being, which is the industry recognised standard for connections which will be burried in the ground for installations like this?

There seems to be two methods of connections from what i can gather.

1. IP68 SWA joint box (removable screw on lid) with E1W swa glands for waterproofness and IP68 compression glands for flex to bollard. Approx. cost

 

Alzee

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Just for the shear fun of it, I'd do a line of 6 Scotchcast y-splices, ending with your main swa terminating at the 7th post.

Those resin filled splices do a great job, if assembled correctly. I guess the price would be very competitive with what you have already costed out. I'd say the time to assemble a splice would be a lot less too, but you can't backfill until the next day though.

 

cheggers

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bring the swa up into the posts and make off the swa's with bw's with a banjo to continue cpc. job done.

 

wotnoearth

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thanks for info so far.

ALZEE: never used scotchcast y splices. looked it up on the net cannot find distributor in the uk. was going to use 3 core swa. Can you use those y splices on 3 core and if so how would you connect? The American web site suggested some sort of special clamp.

Zeespark: again, never used hi-tuf. Is it as good/ resilient as swa? Are there two layers of insulation with the outer layer like reinforced insulation? I guess it would be fairly easy to terminate (maybe just strip back and connect straight in to terminals at end of flex in post lights.

cheggers: thanks for suggestion. Will see if I can do that. The post comes with flex already fitted with a connector block for fitting to the supply cable. I know I have to continue cpc, but excuse my ignorance, what do you mean by bw's. Also do you think it would be ok to terminate with swa gland inside the post without fixing it to an enclosure. I guess because it is within the post it would be classed as an enclosure, but what about the cable terminals not being restrained? I have to say it would be the cheapest option by far if it can be done. Thanks!

 

cheggers

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Bw's mean the type of swa gland it is a normal swa gland were as a cw is a waterproof one

the connection does not need to be fixed as the cables are buried in the ground and are not subjected to any strain

 

Alzee

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Link to 3M website showing branch joints (Y-Splice).

http://solutions.3m.co.uk/wps/portal/3M/en_GB/EU-ElectronicsElectrical/Home/ProdInfo/JointsTerminations/ProductCatalogue/?PC_7_RJH9U5230GE3E02LECIE200OV1_nid=TTB4Z0BL3MbeBVTJ7SXCQSgl

The kit would be supplied with either crimps or a terminal block, the connections are wrapped in insulating tape, segregatted from each other, the armour is linked using braided straps and fancy wrap around clips to secure.

The two halves of the casing are clipped together around all the connections, cable entries are taped up to encase resin.

Mix and pour resin, leave to set for say 12 hrs or whatever. Bob's yer ma's brother.

The website also has a huge list of suppliers from around the country.

By the way, Cheggers solution is the way i'd probably end up doing the job, quick and cheap whilst still practical and safe.

 
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