Abstract: A nonvolatile fail-safe system providing protection from bus fault propagation for a multi-channel electric power generating system includes a controller which provides excitation control and protection for a first generator unit, position control for its generator control breaker (GCB) and position control for a bus tie breaker (BTB); protection logic which generates a trip signal for the BTB when a bus fault is detected isolating the load distribution bus from the tie bus, and thereafter generating an excitation isolation control signal and a GCB trip signal isolating the load distribution bus from the generator unit upon sustained presence of the bus fault. A latching generator control relay is electrically coupled in series with the excitation control and is responsive to the excitation isolation control signal for de-energizing the generator by isolating the excitation control.