A bolted short circuit occurs in the series R-L circuit of the given figure with V = 30 kV, X = 10Ω , R = 0.9Ω, and with maximum dc offset. The circuit breaker opens 3 cycles after fault inception.

In the first part of this series, featured in the February 2011 issue, we considered the selection of the protective devices of a low-voltage induction motor supplied from a motor control center (MCC) ...

Adding a clamp circuit to the well known current-limiter protects the "pass" transistor from over-currents when load faults occur. Most readers are probably familiar with two-terminal current-limiting ...

For utilities, proper protection against high voltage transient overvoltages and overloads is critical to ensure maximum life of their power transformers. Failure to do so can result in significant ...