Examples described herein provide an electric power distribution system (EPDS) that includes a transformer rectifier unit (TRU) that receives alternating current (AC) electric power from an AC electric power source during a first state of operation. The EPDS further includes a direct current (DC) electric power source that receives the DC electric power from the TRU during the first state of operation. The EPDS further includes a DC essential bus that receives the DC electric power from the DC electric power source during the first state of operation and that receives the DC electric power from another source during a second state of operation. The EPDS further includes a controller to selectively engage a diode bypass contactor to enable a diode during the second state of operation, and selectively engage the diode bypass contactor to enable a diode bypass during the first state of operation.