Kitchen Grid Cpc’s

[EquinoxElec]

Hi guys, It could just be me being daft here but I’ll ask the question anyway!
I don’t use multi gang grid switches too often but I have two to fit currently. Both have a mixture of ring main and a few appliance radials.
Would you earth the yoke with the cpc from one circuit and keep all the other cpc’s paired up but separate or would you combine all cpc’s together...ring included? I’m just thinking doing the latter might affect individual circuit r1+R2 readings?
Any thoughts appreciated!

 

[Risteard]

Hi guys, It could just be me being daft here but I’ll ask the question anyway!
I don’t use multi gang grid switches too often but I have two to fit currently. Both have a mixture of ring main and a few appliance radials.
Would you earth the yoke with the cpc from one circuit and keep all the other cpc’s paired up but separate or would you combine all cpc’s together...ring included? I’m just thinking doing the latter might affect individual circuit r1+R2 readings?
Any thoughts appreciated!

Personally I would connect all cpcs together. This will reduce the impedance and the touch voltage. Parallel Earth paths are often unavoidable anyway and are desirable, although you may need to verify each one separately. Hence "during erection and on completion".

 

[pc1966]

If that is the only common point for CPCs outside of the CU, then if you disconnect both ring ends at the CU to do the RFC loop test it won't make a difference.

Depending on the number of CPCs though you might find it impractical to tie all together, so maybe choose the highest current one as the box earth so at least you know for sure it meets the adiabatic limit in the event of a fault.

 

[EquinoxElec]

Thanks for the thoughts guys. There aren’t masses of them so I think I’ll opt for jointing them all at that point and placing a flying lead on the yoke....post testing of the appliance radials & ring.
Input appreciated

 

[richy3333]

One lot in a Wago, other circuit to back box and yoke, label up?