Conduit used as earth

[m4tty]

Thanks deke. The Backboxes don't have earth jumpers at present but I do intend to do this. All sockets switches are standard white plastic. What size earth cable should I use for these? Thanks again for your time

 

[Lee321]

here you go matty

from what you've described

i've drawn your old sunken CU with the new cu on top all is good

example 1 conduit goes to a socket and for what ever reason you can only get 2 cables in the conduit. you need to have a good earth to the conduit. the conduit needs to be mechanically sound throughout its length then you need to beable to pick up a good earth off the back box to the earth terminal on your accessory

.

 

[Lee321]

Thanks deke. The Backboxes don't have earth jumpers at present but I do intend to do this. All sockets switches are standard white plastic. What size earth cable should I use for these? Thanks again for your time

your earth need only be half that of the line conductor

however in the circumstance i'd go up a size unless its getting physically to big

 

[Evans Electric]

Thanks Lostit, that sums up what I was trying to say. M8 , your sockets would be relying on the two plate screws to pick up the earth from the back box, a typical 1960s method. Are there earth terminals actually fitted ? I'm thinking if you can't get a decent Zs you would be rewiring , in which case an earth wire can be installed.

If fitting jumper wires they can be 1.5 mm . G/Yell.