My advice...be very careful disconnecting neutrals...especially on 3 phase systems... i have seen a few which didnt end well for the sparky.

Its like thinking you are too clever and dont switch off the light circuit... but instead just turn off the switch...thinking all is good... the light in the room next door is switched on and it bites you.

I have also seen a few nasty outcomes with sparkies working on single phase socket outlets in office blocks which are fed via a 3 phase system... they get all the neutrals mixed up and dont label the wires... it happened to me a long long time ago... I blew all the computers in an office next door to where i was working on the same floor.