Curious Question on First Fix

[leevis]

Hi
Really curious question and I hope someone will be able to answer, I have had the first fix done on my lighting etc and I have lots of 'loops' hanging down, I am guessing that the bottom of the loops will be cut and one end connected to A and one to B, on a circuit I would guess that on each light fitting A (from the consumer unit) would be connected on one side and B on the other side and then the B end would connect to the A end etc etc.

How to electricians know which is A and which is B? I can't see any marks on mine, do they put a tester on each end to determine which is which?

 

[ETAF]

isnt it just a radial circuit - so they join at the rose , doesnt matter which is which as its just a join L-L N-N & E-E
then from the live another wire goes back to the Switch and returns a Switched live - so 3 T&E to each switch , except the last one on the radial circuit

Picture here
https://www.practicaldiy.com/electrics/lighting-wiring/light-wiring-explained.php

 

[davelx]

More detailed explanation in the wiki: https://www.diynot.com/wiki/Electrics:Lighting-Circuit-layouts