How do you R1+R2 test a lighting circuit spured from a ring main

[petertwine]

Hi Just wondered if anyone can give me abit of advice when inspecting and testing how do you go about a lighting circuit R1+ R2 and Zs.. ect when it is spured from a Ring Main circuit. Any info would be gratefully received
thanks
pete

 

[BillyBoBob]

I'm positive on this but the Light is a LOAD and sholud not be tested as it isn't part of the installation.
You wouldn't test Zs on a hoover you plugged in would you?

 

[BillyBoBob]

Ok I'm now looking WAY to deep into this. However.
If the light or lights are wired in T/E with switches ect from the FCU then they would become part of the fixed installation.
The Ring Final Circuit would become a Distribution circuit for the FCU.
The light wired from the FCU would be a Final circuit.
So yes all tests would be required from the FCU in order to ensure that the BS1362 fuse blows within 0•4 seconds.
It's the same principle as feeding a sub-board in your garage from a consumer unit in your house.