Testing High-Voltage Breakers Online

Circuit breakers used in power systems perform critical functions of fault detection and circuit disconnection. Because faults are abnormal conditions, they can occur infrequently with years often elapsing between breaker trips. Infrequent trips make periodic testing a necessity, but it can be difficult to properly test live circuits without interrupting normal operations or damaging equipment. T&D World reports on a portable test set that performs live trip testing on high-voltage circuit breakers in electrical transmission and distribution systems. The test set uses current sensors to measure amperage and synchronize injection of additional power in terms of frequency and phase.