bayoubare ......"-- you do not ever recommend test a cable ? Even if the entire switchgear is de-enegized a cable must be moved to be tested. Using your logic that may cause a fault when it is re-energized so it should not be done?"
you are correct, a cable moved/tested whilst de-energised might well develop a fault when re-energised but the big (and probably life saving) difference is that when I re-energise a cable I can be in a different room whereas to move an energised cable as you are suggesting I'd have to be in the same compartment
Turning it off gets my vote too