M
macrylinda1
The actual supply is not switched off, the installation past the main breaker is switched off granted but not the supply. Anyone just about to take the 2391 practical may be confused as books including GN3 and OSG use the CRIPLER method and this is the way i've been taught to test within my 2391 course;Beg to differ here IMO the safe isolation must be done prior to the Ze test as you are removing the main earthing conductor to the installation. I stated that the Ze test had to be done with the supply switched off not that it was a dead test
Dead tests:
Continuity of circuit protective conductors
Ring final circuit conductor continuity
Insulation resistance testing
Polarity