Electrical Load:

The amount of electricity that is applied to the switch or the circuit.

Gap:

The shortest straight-line distance between two separate contacts.

Inrush:

The initial transitory high-level of current at contact closing (making). A characteristic of capacitive and some resistive loads. The inrush currents can be large and long enough to cause severe degradation of the contacts. See Resistive Load. Capacitive Load. Power...

Contact Gap:

The distance that separates two contacts when the circuit is open.

Dielectric Breakdown:

Rupture of insulating material when the electric stress exceeds the dielectric strength of the material (Voltage Breakdown).