Principle of transformer neutral-point earthing switch operation
(1) If several transformer in parallel on different buses running, you need at least one of each bus transformer neutral point earthing to prevent bus connection breaker hopped a bus after becoming grounded system. (2) if the power at low voltage side of the transformer, the transformer neutral point grounding must be directly, in order to prevent high voltage breaker transformer insulated neutral system. (3) if the number of transformers in parallel operation, normally only allows a neutral-point earthing of transformer. (4) the transformer prior to power or charge, to prevent circuit breaker three-phase period or non-full phase input voltage transformer must be in front of the power or charge of transformer neutral-point earthing.