As long as the circuit you are working on is isolated then it's safe. Like you say one side of the main switch will still be live but you can use this side to prove your voltage indicator if you don't have a proving unit, and also for testing your Ze
The only ways to completely make the CU safe are to either pull the main fuse (which you're not supposed to do) switch off an existing isolator or request an isolator fitting by the dno, there's no way this would be practical on every job.
If the main switch is off the busbar will be isolated so you won't see any sparks when connecting a crocodile clip onto it, I can't think why you would put a link between the busbar and cpc to do an IR test though?
The only ways to completely make the CU safe are to either pull the main fuse (which you're not supposed to do) switch off an existing isolator or request an isolator fitting by the dno, there's no way this would be practical on every job.
If the main switch is off the busbar will be isolated so you won't see any sparks when connecting a crocodile clip onto it, I can't think why you would put a link between the busbar and cpc to do an IR test though?
