The fast operation of modern breakers and contactors can interrupt current flow in milliseconds. This sudden interruption of current, creates voltage transients which can cause damage to insulation on loads such as transformers and motors.
Medium voltage surge protection panels are designed for each application to protect electrical equipment insulation from transient overvoltages.
Surge protection panels require an engineered combination of voltage arresters, capacitance, resistance installed in a Nema type 4 enclosure with lug pads for cable terminations.
Isolation switches or contactors for the surge panels are also available.
The equipment must be installed according to specification to be effective.