Transformer Failure

Transformer Failure protection relays & arrestors ensure that it's withstand limits on short-circuit current and power frequency voltages are not exceeded. Impulse over-voltage will happen if lightning stroke falls on an overhead line near the transformer installation. Power frequency over-voltage could occur from the opening of a highly loaded circuit breaker. Transformer insulation protection against these two types of voltage surges are ensured by connecting ZnO type surge arrestor near HV bushing.