An enhanced method of providing sensitive bus fault protection

The application of bus fault protection in industrial facilities has been primarily limited to overcurrent relays located at the upstream breaker. This does not always provide the best protection for bus faults. The protection sensitivity is limited because of the need to coordinate with other downstream overcurrent devices. This paper describes an enhanced method of applying sensitive bus fault protection using digital overcurrent relays. In addition, this method provides both downstream feeder breaker backup protection and relay backup protection.