Question

What is the best approach to isolate a small load sensitive to harmonics from a very large load, which produces high harmonic currents?

Answer 1

The best way to isolate a small sensitive load from a large load with high harmonic current is by using a relay and a circuit breaker. When any fault occurs in the line connecting large and the small load, large amount of fault current starts flowing through the line and produces harmonics or disturbances. When a relay and breaker are present, the relay senses the fault current flowing and opens the circuit breaker thus isolating the large and small load. The relay has predefined settings and when current exceeding the nominal value flows through the line, the relay senses the fault and opens the CB isolating the loads.