Borrowing a cpc from another cct for lighting cct coded C2 in PE magazine codebreakers.

So if you really do "pinch the cpc from another circuit", it does not comply in many TN systems.

I guess it's possible that one T&E can run in the immediate proximity of another T&E (like a G/Y run alongside SWA) - even extraneous-conductive-parts may be used as c.p.c.s (543.2.1 (vii)) -so certainly no requirement to be part of the same wiring system. In any event if there was an upstream RCD all it would take would be a flick of the pen by the designer to nominate that as the ADS device.

So what's the actual danger from such a non-compliance - compared with the same arrangement on a TT system (would be entirely acceptable) what's the additional danger? Does it really equate to a C2?

    - Andy.

Thanks for all replies.

                          Regards,

                                    Hz

I like an obvious separate C.P.C. for each separate final circuit in most cases. This is illustrated in modern consumer units by having numbered N and E bars to allow line, N and C.P.C.s to be connected in order. This makes fault finding easier if the original cables have been correctly terminated. If say a lighting final circuit used another lighting final circuit's C.P.C. and the first is disconnected for any reason you lose two C.P.C.s. This could happen if we did not realise that two circuits rely upon one C.P.C.

Z.

That`s one thing I like about ganging switches on different lighting circuits. It often means that in reality although each circuit cpc path is checked on it`s own there are often a link or two at various parts of such circuits thereby givind i) cpc redundancy & ii) lowering effective R2 readings. Commonly 2 or 3 circuits have such intentionable or unintentionable interlinks in domestic properties.

Tin hat on and ducked down below the parapet !

That`s one thing I like about ganging switches on different lighting circuits. It often means that in reality although each circuit cpc path is checked on it`s own there are often a link or two at various parts of such circuits thereby givind i) cpc redundancy & ii) lowering effective R2 readings. Commonly 2 or 3 circuits have such intentionable or unintentionable interlinks in domestic properties.

Tin hat on and ducked down below the parapet !