My low voltage system is solidly neutral grounding, but due to some reason we need to change some system to be ungrounded, current practice is just disconnect the neutral point, with precaution, among of them is de-energizing the transformer when we intent to re-connecting the grounding lead. All downstream insulation such as cable, etc are already designed to meet ph-ph voltage insualtion. Later, we plan to change it permanently by using delta-delta tx. On top of this info, each transformer is dedicated to serve service single load, ie 3 phases motor-pump, using underground cable, min distance from transformer to the motor. All equipment panel etc is grounded/bonded to have min step/touch voltage.

Technically, we calculated that capacitive current may be appreared is very low, we may proceed it.

My quesition: what is safety issue on this ungrounded system? if the system is intended to serve/cover big load or area, yes .. we do need take care, but this is for a single load/motor. What is your opinion? pls


gg