I have observed that for all ATS scheme there is delay incorporated in the relay before closing of the Bus tie breaker.I have read that the residual voltage needs to go down to 25% before closing the Bus tie breaker.But in case the Motor feeders are contactor feeders will there be a residual voltage in the bus ,As when the incomer trips all contactor feeders also trip please advise.Are there any reasons for the delay to be incorporated.
Auto Transfer Scheme for Low Voltage 415V Systems
Re: Auto Transfer Scheme for Low Voltage 415V Systems
