Using adaptable box to terminate SWA

[amateurSparky]

Hi
My problem is I've purchased a double insulated high integrity Consumer unit. THerefore it doesn't bloody have any knockouts for terminating SWA. I'm going to fit an adaptable box so I can convert from SWA to 6mm T & E cable. Is this suitable for my urpose

http://www.screwfix.com/p/appleby-adaptable-box-knockout-box-galvanised-225-x-225-x-75mm/81294

Is it me or that adaptable box is rather expensive? I don't mind paying extra if it gets the job done though. Should give me plenty of room to work with!! Am gonna need it since my swa terminating skills are none existant!!! Might have to phone a friend

 

[RF Lighting]

It's dear because it's freaking huge! Nearly a foot square!

Assuming 6.0mm² t&e to 6.0mm² SWA then you want something like a 100mm x 100mm x 75mm to make the joint.

Alternatively, depending on how sturdy the CU is, drill a 20mm hole into the CU, gland in the SWA as usual, and fit a piranah nut to earth the SWA and gland.

 

[amateurSparky]

LOL.
I was thinking using it for storage as well!!

Ok this is more like it a fiver
http://www.screwfix.com/p/appleby-adaptable-box-knockout-box-galvanised-150-x-150-x-75mm/61022#

Thanks RF lighting. My mate already suggested that. I think I'll go with the adaptable box. JUst in case I manage to break the consumer unit somehow. I have a track record of breaking things am afraid.

 

[sparkwright]

If something like 6 mm2 SWA, you could use a galvanised conduit through box. Leave the wires long enough to run through the through box, and into the consumer unit.

Run a 4 or 6 mm2 (for example) earth from the consumer unit earth terminal to the earth terminal on the through box. A ring terminal crimp will be needed here.

 

[PrenticeBoyofDerry]

If it is possible for you to locate the adaptable box to next to the CU.
Terminate gland of SWA at adaptable box but keep conductor cores of SWA long enough to enter KOs of CU, so they can be terminated within CU without jointing them within the adaptable box.

Blast! need to up my keyboard speed!

 

[Click4]

This would be a more ideal size,

http://www.screwfix.com/p/appleby-g...FBb0NMnc2brGZNtGkJc3QcQXPfX51pJyV1!-467609224

it also has the knockouts.

worrying thing though is, if you are an a sparky that you are asking if the box is suitible when you should already know, and that if as a spark you cant terminate SWA? those are pretty basic things. You can also get a plastic 32mm surface mounted back box, with a round knockout 1 side.. which you can terminate SWA into.. if you butt that against the side of the consumer unit you can then knock out the top for the T&E.

like this,

http://www.tlc-direct.co.uk/Products/MKK2181.html

then cover with a blanking plate. Safer as well, being non metalic.

then inside, to save on space, use WAGOs which are a maintenance free connection, and dont take up as much space as Choc Blocks.

http://www.tlc-direct.co.uk/Products/WA173.html

im not criticising here or personally attacking you, as I myself usually result to going down the council notification route and having to pay £100 a time to hire test equipment for a week as im not a spark each time ive had to notify so I can test my work before powering up, even though council test again after... just if you arent a spark, and asking questions like that id be a little concerned about you changing your consumer unit... it would also require signing off or council notifaction and testing to satisfy part p.

 

[JohnW2]

You can also get a plastic 32mm surface mounted back box, with a round knockout 1 side.. which you can terminate SWA into..

If you mean standard 'plastic' surface boxes, they are seemingly made of one of the most unforgiving brittle substances I've everhad the misfortune to deal with, and are, IMO and experience, very likely to crack (if not shatter) if they are at all stressed by the SWA (or even when tightening the gland). A PVC one would be much less brittle, but may possibly distort if stressed too much by the SWA.

Kind Regards, John

 

[amateurSparky]

In my opinion it never hurts to ask someone whos more experienced than I am. Am a trainee at the moment. I'm rewiring this house to become nappit registered. To be fair how else am I supposed to gain experience if nobody I've asked is willing to take me on as a apprentice? Am sure doing a damn better job than the last electrician who taped two pieces of T & E cable together. Plus am supervised by another electrician. I will consult his advice.

 

[Click4]

true, that is a disadvantage of plastic boxes.

in terms of stress some of that would depend on how the cable is clipped
so metal box does have its advantages, what i would of done personally is drill the holes in the wall get the plugs in the wall where you want the final position of the box, but dont screw box to the wall yet.

terminate the SWA into the box with the box still not secured to the wall.

then once fully terminated into the box, secure the box to the wall, then clip the SWA in such a way that it doesnt stress the box.

but it does depend on the situation like if SWA is going straight into the box, or if it has bends prior to the box, or if you have a good amount of cable running up or down the wall or just a few inches... etc.

Metal box though i agree would be stronger, also requires earthing to the SWA cable and outgoing cable.

 

[Click4]

In my opinion it never hurts to ask someone whos more experienced than I am. Am a trainee at the moment. I'm rewiring this house to become nappit registered. To be fair how else am I supposed to gain experience if nobody I've asked is willing to take me on as a apprentice? Am sure doing a damn better job than the last electrician who taped two pieces of T & E cable together. Plus am supervised by another electrician. I will consult his advice.

Yep, I agree, nothing wrong with asking and that is the problem with the system as well.. while there are lots of great electricians who do the job properly there are equally lots of electricians who do a job which is at the same level as DIY.. if not worse in some questions yet they can call themselves an electrician and sign off their jobs as safe.. even if they arent. Yet somebody like me, who does a respectable job, follows all the regulations, does all the calculations... ~AND tests.. is not legally allowed to do most electrical work without council notification and paying large fees.

I find a good way to learn about what products are available is browsing through catalogues like TLC which they send me every few months... find some great products which I would not of otherwise known about.

If you are a trainy that explains the question, lol would be worried if you was a fully qualified spark asking that question its a bit of a DIYers question.

 

[JohnW2]

.... terminate the SWA into the box with the box still not secured to the wall... then once fully terminated into the box, secure the box to the wall, ...

That's the point at which you are likely to hear that stomach-curdling little 'click' (if it didn't happen when you tighten the gland)

.... ...then clip the SWA in such a way that it doesnt stress the box.

.. but too late, if the box has already cracked.

I am, admittedly, painting a rather black picture - maybe it's just me! With care, one can often get away with it, but I have had a good few less happy experiences (and not only with SWA)

Kind Regards, John

 

[Click4]

lol, yep it is a rather black picture.

I dont disagree with what you are saying though, as you have valid points.. ive had some crack myself.

But also had lots which dont when care has been taken.

So both have advantages and disadvantages.

Plastic - Safer.. but cracks

Metal - stronger, but need to ensure proper earthing for safety.

eathing not so much a problem for a sparky, but im sure theres many DIYers who dont bond the box to the earthing wires and metallic outer of the SWA... and rather just connect 1 wire of the SWA to the T&E earth wire coming out the other side with no bonding to the metallic box or SWA outer metallic sheathing.

 

[JohnW2]

eathing not so much a problem for a sparky, but im sure theres many DIYers who dont bond the box to the earthing wires and metallic outer of the SWA... and rather just connect 1 wire of the SWA to the T&E earth wire coming out the other side with no bonding to the metallic box or SWA outer metallic sheathing.

Maybe - but I really think that if somene does not have the knowledge and skill to terminate SWA properly, with a gland, then they really shouldn't be working with SWA at all.

Kind Regards, John

 

[bernardgreen]

Untitled

• bernardgreen
• 10 May 2009
• 17

 

[JohnW2]

Untitled

• bernardgreen
• 10 May 2009
• 17

Mr Eddystone would be proud of you! It's good (and rather nostalgic) to see an electronics man at work

Kind Regards, John