Surge Protection

The electrical engineer doing the analysis, evaluation, and application of the surge protection of the power system surge protection must be very well experienced on all the aspects and issues involved in the system surge protection because the system is a variety of system configuration - overhead, underground, combination of overhead and underground; a variety of source connections. Near substations (small or large), near generating stations (small or large) near switching stations (small or large), near capacitor banks; a variety of loads - non-linear, linear, small / large motors (cycling / non-cycling), high transient loads, and so forth.

Surge protection must be prudently evaluated and discriminated. In overhead systems LV to HV, lightning arrester protection is a common choice of protection because of lightning strikes either direct or induced. The protection principle in lightning arresters is different than the surge protection being used in indoor low voltage surge protection. Surge disturbances on overhead lines can be lightning surges (very high voltage transient that may be followed by high current surge). There can be also switching surges both in overhead and underground systems when switching are made on the source or on the loads.

On the low voltage systems there is a need to analyze what kind of surge disturbances are likely to be encountered. Indiscriminate application without a study and evaluation may only be a waste in investment and sometimes becomes more of a source of problem rather than a help. Outdoor lightning arrester protection devices, I recommend should be delineated / discriminated from the surge protection device to avoid confusion in application.