Thoughts please, SWA vs T&E

[GBDamo]

I have a TPN board that will feed 8-10 sub boards. The loads on each board are negligible 5-10 amps peak but mostly 1-2 amps.

The distribution circuits will be fed in 6mm mostly for VD reasons but also to allow some selectivity on the OCPD(MCB) my dilemma is SWA or T&E.

The route is 98% tray before entering a room and feeding a surface mounted consumer unit.

For aesthetic reasons they want the cables in the wall, fair enough, but I'm in a catch 22.

If SWA I'd never be able to gland into the back of the CUs and the SWA would end up surface, if T&E the cable would be in a timber partition but less that 50mm deep thus requiring RCD which completely negates the principle of sub devision of circuits.

1, Am I going OTT worrying about this c0.5m drop from the ceiling to the back of the CU?

2, My "Solution" is to mount a galvanised box above the ceiling, gland the T&E through into some earthed steel flexicon, down inside the wall and into the back of the CU.

3, Am I missing a more obvious simpler solution?

Thanks.

 

[davesparks]

Gland the SWA into a flush metal box behind the CU, can be a normal back box, terminal box or adaptable box.

In a stud wall I've even glanded SWA into a galv inspection elbow and bushed that onto the back of the CU.

 

[westward10]

As above use a steel adaptable box fixed to the back using its four cover fixing points.

 

[Dustydazzler]

I have seen people gland into a through box during 1st fix ( which is often left floating and just pull the single cores through the plaster board wall

 

[GBDamo]

I jave thought about glanding off behind the CUs but aren't these supposed to be accessible for inspection?

 

[westward10]

If the armour is not acting as the cpc then it is not important as the other end will be accessible.

 

[Dustydazzler]

I jave thought about glanding off behind the CUs but aren't these supposed to be accessible for inspection?

a club hammer to the plaster board would soon make an inspection hole

 

[timhoward]

The "last few cm" of a distribution circuit supply requiring RCD protection is one of the irritations of the regs.
I've long thought that anyone who decides to go drilling in the 20cm above a CU deserves to become an integral part of a new circuit.
Bring back the 16th edition!

 

[davesparks]

The "last few cm" of a distribution circuit supply requiring RCD protection is one of the irritations of the regs.
I've long thought that anyone who decides to go drilling in the 20cm above a CU deserves to become an integral part of a new circuit.
Bring back the 16th edition!

If its just the last drop down/up to the CU then it's easy enough to give it mechanical protection. A bit of galv conduit or even a metal plate is all you need.

 

[James]

I go out flying kites with the grandkids far more often than I drill holes in the walls of my house.
their is some loose advice out there if you search for it that recommends not to fly kites near overhead power lines. (The sparks amongst us will already know it’s a bad idea)

there are regulations that prohibit running cables an inch below the surface from a consumer unit to the ceiling (230v) where no sane person would drill a hole but a bit of advice not to mess with the 11,000v overhead lines.
over the top maybe?