Paul,
we dont actually come into contact, ouch ! (i have only once, and it cost me a lot of time off)
We are sometimes called into a lot of commercial properties to fix lights and the such like and most of the time the identification of circuits and phases is not done, so you end up removing the plates from switch gear and finding a bunch of red cables and the theory should be that that set up is red phase 230v.
then when you start testing you get two different phases and sometimes three.
There are requiremnts within the regulations over here to identify each circuit and to what breaker it is fed and from what phase,
IE R1/DB3/LT1
Red phase / Distribution Board 1 / LighT number 1.
if the R changes to Y or B you automatically know you have three phase within, (also by the warning notice, Danger 415 Between Switches, that should also be placed on or about the switch gear.
Bye for now. John H
