lighting neutrals connected to socket neutrals

[soloheadbeg]

Hello

I've noticed in my 1970's bungalow that the 1.5mm2 neutrals from the lighting circuits return to the consumer unit by connection to the neutrals in the radial socket junction boxes. Is this safe? Was it standard practice in Ireland in those days?

Cheers

 

[ajrobb]

It is not safe as the circuits will still be live when either one was supposed to be isolated. Say the socket cicuit's fuse was removed and the cable for the sockets removed from the CU - should be safe you think. Someone tries to turn on a light, they don't work but now both circuits are at lethal voltage.

 

[plugwash]

As ajrobb points out iit poses a hazard to those maintaining/modifying the system. BS7671 bans it for this reason I do not know if irish regs do the same. Depending on the ratings of the circuits it could also cause overloading but not seriously so (and mild overloading just tends to shorten the lifetime of cables)

So it's something to be aware of so you can take appropriate precautions (best option is to isolate the entire installation before commencing any work on it) when working on the installation and to sort out when the opportunity arises but it's not something that poses an immediate hazard to users of the installation.