Both earths?

[masted75]

Hi all, hope you can help.
I'm fitting a new light switch (metal with 3 switches). There a two 3-core cables coming into the back box, so there are two earth cores (one from each cable). One of the earth cores has snapped - I tried to extend it with a bit of new earth core and a connector block but it was already a tight squeeze getting the faceplate to go onto the back box and having the connector block in there, despite being small, is just too much - not enough room in there now for it all to squeeze in.
I would rather avoid fitting a new back box if possible (and having to hack some brick away) so my question is: do both earth cores have to be connected up to the faceplate for it to be safe (with a loop of earth going back to the box) or will just one earth core connected be alright - so the snapped one can be left out.
Sorry if it's a stupid question for more experienced people.

 

[bernardgreen]

YES both earth wires MUST be connected.

One will be bringing the earth to the switch, the other will be taking the earth to other lights and switches. If you only connect one of them there will be light and switchs without a working earth earth connection.

And as you have metal switches these have to have a working earth connection.

 

[wingcoax]

Your back box should have an earth terminal, connect the short wire to this and link to the other earth in the switch plate. This will complete the earth links to other equipment.

 

[bernardgreen]

Your back box should have an earth terminal, connect the short wire to this and link to the other earth in the switch plate. This will complete the earth links to other equipment.

NOT a good idea.

Yes it will complete the earth continuity but that will be via the screws holding the face plate to the box. If they become loose then continuity will be lost or compromised leading to lossof safety earth at other lights and switches.

Connect BOTH cable earth wires to the back box and then take a lead from there to the switch plate.

 

[stargazer]

One of the earth cores has snapped - I tried to extend it with a bit of new earth core and a connector block but it was already a tight squeeze...not enough room in there now for it all to squeeze in.

How are your soldering skills?
You might get away with a soldered joint covered with the normal green / yellow sleeving.

 

[wingcoax]

Sorry BG i said link with a wire.

 

[masted75]

Thanks for the advice everyone. It's all sorted now and done.

 

[JonoPashley]

Your back box should have an earth terminal, connect the short wire to this and link to the other earth in the switch plate. This will complete the earth links to other equipment.

NOT a good idea.

Yes it will complete the earth continuity but that will be via the screws holding the face plate to the box. If they become loose then continuity will be lost or compromised leading to lossof safety earth at other lights and switches.

Connect BOTH cable earth wires to the back box and then take a lead from there to the switch plate.

metal switches tend to have a earthing terminal on them.