Jointing big(ish) cables

[Stueeee]

Thanks to all for the useful replies. I did consider a bunch of Henley blocks but they would have needed to be enclosed to protect against the 'rough and tumble' of large chunks of metal in the workshop. Would be an OK solution if they were up and out of the way as at my workshop's distribution.

I had assumed that the choc block terminal strips didn't go bigger than 60A -the biggest that TLC list. But from searching ebay I found this listing (among others) https://www.ebay.co.uk/itm/324162768153?hash=item4b799b4d19:g:wwMAAOSwzvtigmAM&amdata=enc:AQAIAAAAwPig8s7zJZFmvVaQOt0j24lfp3wY9Vq7hr7i3Q/az4ZZoAHxkhdyTAnlyD4mb53+tLqlUCdQguLazqfc8ia8lCSfOdlZ45k+UZwnpUnEBLnK7Sv+xd8w3RiLTiVBLc3Dttycak03ZdodhyZvf//miVC5oJnsHNJ9JbtW/fbCTUlC0xozLXSL+ofDOQ7ovL1hRQV3dZQAouAoDCCgyAaHr+oWivuFz48hpD4Fn0gmqDEF1doiryyEyDnlXdS8Za9Rzw==|tkp:Bk9SR-rGmrj8Yg
Where they list up to 100A, combined with a 150 x 150 box, hopefully I'll get the job done this time.

 

[Hotstuff]

Please do be careful Stueeee. As a layperson it’s never easy to know when well meant advice offered on forums is really based on qualified experience or perhaps just their best guess.

Jointing TP&N circuits wired in SWA needs plenty of room and proper fixed terminations, ideally one terminal per conductor to be terminated. I would strongly advise against using any kind of strip connector for this type of application.

Bearing in mind that there will be 415 Volts between each of the phases, it might be wise to use four fixed single pole Henley blocks within a large galvanised steel adaptable box.

Do allow plenty of room within the box to allow the cables to sweep comfortably into their terminals without the need to use any force.

This advise does not take the design of your circuit into consideration, and assumes that you will be testing before energising the circuit.

Please don’t shoot me down as I’ve only commented in the interest of safety.
I don’t want Stueee’s next post to be about the best way to put out a fire or first aid tips for electrocution.

 

[dan.taylor.1]

I've a box full of Henley type blocks if you need some.

 

[brightspark]

I presume you've already tried with the block released and then wire-up and re-fitted? I did notice that the block has nuts and not screw heads, just to make things harder. If it's armoured cable (?) then a 'trouser' box would be better suited. Although it'd be tight for space again.

Metpro 20mm Galvanised 3 way branch "Y" BESA box

Buy online Edwardes Metpro 20mm Galvanised 3 way branch 'Y' BESA box

www.edwardes.co.uk

your lucky if you get 2x 2.5mm flat twin and earth cables in that. i posted the one to use. im joining 2x 10mm 3 core armoured cables in to one tomorrow on a job

 

[prepman]

your lucky if you get 2x 2.5mm flat twin and earth cables in that. i posted the one to use. im joining 2x 10mm 3 core armoured cables in to one tomorrow on a job

True...

 

[brightspark]

Thanks to all for the useful replies. I did consider a bunch of Henley blocks but they would have needed to be enclosed to protect against the 'rough and tumble' of large chunks of metal in the workshop. Would be an OK solution if they were up and out of the way as at my workshop's distribution.
View attachment 425778
I had assumed that the choc block terminal strips didn't go bigger than 60A -the biggest that TLC list. But from searching ebay I found this listing (among others) https://www.ebay.co.uk/itm/324162768153?hash=item4b799b4d19:g:wwMAAOSwzvtigmAM&amdata=enc:AQAIAAAAwPig8s7zJZFmvVaQOt0j24lfp3wY9Vq7hr7i3Q/az4ZZoAHxkhdyTAnlyD4mb53+tLqlUCdQguLazqfc8ia8lCSfOdlZ45k+UZwnpUnEBLnK7Sv+xd8w3RiLTiVBLc3Dttycak03ZdodhyZvf//miVC5oJnsHNJ9JbtW/fbCTUlC0xozLXSL+ofDOQ7ovL1hRQV3dZQAouAoDCCgyAaHr+oWivuFz48hpD4Fn0gmqDEF1doiryyEyDnlXdS8Za9Rzw==|tkp:Bk9SR-rGmrj8Yg
Where they list up to 100A, combined with a 150 x 150 box, hopefully I'll get the job done this time.

who put the mains tails in to the metal enclosure to the rcd thats a big no no drilling 3 seperate holes for them .they should all go though one gland or a metal bush .ive just altered the same thing on a job to compy for a test . it causes eddy currents and overheating . here https://www.google.co.uk/search?q=e...d&sclient=gws-wiz#vhid=zNudhJuBl1lchM&vssid=l

 

[Stueeee]

Interesting, not sure that the RCD enclosure is metal -the front plate definitely is -I'll check that out once I've got rid of my current lurgy -hopefuly not Covid for the third time...

 

[Dave-sparks]

The RCD Enclosure may not be metal, but the main switch and switchfuse are and they look like the tails are not all passing through the same hole either.

 

[Dave-sparks]

this is what you want plenty of room fits 10mm cables in no probs on armoured https://www.tlc-direct.co.uk/Products/WK1010B.html

Personally I avoid using plastic boxes with SWA whenever possible, I'd always use a metal box or an SWA joint kit.

 

[Justme]

Put the top cables into the bottom of the choc block. Gives you more room to bend / flex the cable.
Put the thinner ones in the top.

 

[Stueeee]

The RCD Enclosure may not be metal, but the main switch and switchfuse are and they look like the tails are not all passing through the same hole either.

Checked last night, the RCD box is plastic. Interesting though regarding seperated cables feeding the switch fuse (labelled 415V supply to remote garage) because unlike the main workshop (which I wired myself before the later regs) the switch fuse along with all the stuff in the remote garage was subject to a 'Part P' inspection, which it passed OK. Is 'the all cables through the same hole' a recent requirement? I know the physics is hardly new -I can vaguely remember doing Fleming's Corkscrew Rule in school physics lessons 50 something years ago.

Will put moving the cables on the ever lengthening 'to do' list.

Once again thanks to all for the useful replies.

Edit: I may have mis-attributed the corkscrew rule -but schooldays were more than 50 years ago!

 

[brightspark]

Personally I avoid using plastic boxes with SWA whenever possible, I'd always use a metal box or an SWA joint kit.

not much use outside on a wall and needs to be waterproof and theres 8 of them feeding a double socket on each over a 35meter run 10mm in and 10mm out and a 6.0mm up to each socket

 

[MetalMonkey]

Is 'the all cables through the same hole' a recent requirement? I know the physics is hardly new -I can vaguely remember doing Fleming's Corkscrew Rule in school physics lessons 50 something years ago.

Will put moving the cables on the ever lengthening 'to do' list.

Once again thanks to all for the useful replies.

Edit: I may have mis-attributed the corkscrew rule -but schooldays were more than 50 years ago!

The reg you are after is:

521.5.1 - Ferromagnetic enclosures: electromagnetic effects.

The conductors of an AC circuit installed in a ferromagnetic enclosure shall be arranged so that all line conductors and the neutral conductor, if any, and the appropriate protective conductor are contained with the same enclosure.
Where such conductors enter a ferrous enclosure, they shall be arranged such that the conductors are only collectively surround by ferromagnetic material.

Its been a requirement certainly in the 17th and 16th editions, and I believe in the 15th as well, so 40+ years - prior to that I couldn't say!

However, in reality unless you are pulling a lot of amps in an industrial installation, the heating effect is going to be very, very minimal.
One option would be to slit between the holes with a hacksaw which will render it "one hole"

Yup, based of the same principles, although Flemings is more down to motion created by current, Maxwell/Faraday would probably be more appropriate for describing eddy currents, although as you say, its been a while!

 

[Dave-sparks]

not much use outside on a wall and needs to be waterproof and theres 8 of them feeding a double socket on each over a 35meter run 10mm in and 10mm out and a 6.0mm up to each socket

Why not? What's wrong with either option outside?

 

[Dave-sparks]

Is 'the all cables through the same hole' a recent requirement?

Not recent at all, I believe it was first mentioned explicitly in the 13th edition of the wiring regulations, published in 1955.

 

[8ob]

Compared with the older gear new swa is so much harder to work with, even the copper cores are stiffer.

Bob

 

[brightspark]

Compared with the older gear new swa is so much harder to work with, even the copper cores are stiffer.

Bob

turkish cable and its xlpe

 

[Robotstar5]

Compared with the older gear new swa is so much harder to work with, even the copper cores are stiffer.

Bob

That's because it's XLPE instead of PVC, allows it to run hotter, but harder to work with.

 

[Stueeee]

Thanks once again for everyones' input, got the job wrapped up last night.

Used my old clockwork Megger for insulation and confirmed the continuity. Checked the phase rotation using Flukery once the circuit was powered up.