Abstract: A ground fault immune power and data delivery system for downhole sensors is connected to a downhole motor via a three-phase power cable. An AC power supply and sensor data module are connected to only two of the three phases to provide power and data signals to the sensors. During normal operation, power and data signals are transmitted over only one of the two connected phases. If a ground fault is detected on the third unconnected phase, power and data signals continue to transmit over the connected phase. If a ground fault is detected on one of the two connected phases, an isolation module isolates the grounded phase and switches to the ungrounded connected phase to continue transmitting power and data signals. If two of the phases are grounded, the motor shuts off; however, power and data signals may continue to transmit over an ungrounded connected phase.

Abstract: A ground fault immune power and data delivery system for downhole sensors is connected to a downhole motor via a three-phase power cable. An AC power supply and sensor data module are connected to only two of the three phases to provide power and data signals to the sensors. During normal operation, power and data signals are transmitted over only one of the two connected phases. If a ground fault is detected on the third unconnected phase, power and data signals continue to transmit over the connected phase. If a ground fault is detected on one of the two connected phases, an isolation module isolates the grounded phase and switches to the ungrounded connected phase to continue transmitting power and data signals. If two of the phases are grounded, the motor shuts off; however, power and data signals may continue to transmit over an ungrounded connected phase.