CU change--no cpc to lighting ccts.

[ian932]

Is this why we put the earth on the back box????

It is, but the scenario here is that there is no cpc on the lighting circuit

 

[extension15]

As far as I'm aware no one has ever died from touching the screws on a Class 2 light switch..

(with a metal backbox)

 

[PAUL M]

Would a light switch need to have hidden screws as these would be extraneous conductive parts if fitted to a metal back box ??

You used to be able to get P.V.C screws,dont know if you still can,not seen any for a while.

 

[extension15]

Oh you chaps are useless. It was Ext 15 you gave the tip to*sigh*

Blimey Apache, you don't miss a trick:^O

(I take it you have more than one window open on the forum?B-))

Anyway, having read several articles and given sound advice from steptoe..

I had the following choices:

1 Connect both feeds to the same MCB and treat as one circuit.

2 Use single pole RCBO's on the High Priority side of a 17th edition CU.

3 Run a neutral to the required point.

I went for option 1

]

 

[ian932]

As far as I'm aware no one has ever died from touching the screws on a Class 2 light switch..(with a metal backbox)

I've had a right good belt off one when some clown thought it would be a good idea to use the cpc as the third wire for a 2-way circuit and thought it was an even better idea to not sleeve the cpc which ended up touching the box making screws live. Even better the house was sold to landlord by a sparky who had rewired the whole house.

 

[extension15]

I've had a right good belt off one when some clown thought it would be a good idea to use the cpc as the third wire for a 2-way circuit and thought it was an even better idea to not sleeve the cpc which ended up touching the box making screws live. Even better the house was sold to landlord by a sparky who had rewired the whole house.