Short-circuit Current

Short-circuit current is greater than locked-rotor current and may range upwards of thousands of amperes. The maximum value is limited by the maximum short-circuit current available on the system at the fault point. Short-circuit current may be further classified as bolted or arcing.

•Bolted short-circuit current: Bolted short-circuit current results from phase conductors becoming solidly connected together. This may occur from improper connections or metal objects becoming lodged between phases. Obviously, large amounts of short-circuit current will flow into a bolted fault .

•Arcing short-circuit current: Arcing short-circuit current results from phase conductors making less than solid contact. This condition may result from loose connections or insulation failure. When this happens, an arc is necessary to sustain current flow through the loose connection. Since the arc presents an impedance to the flow of current, smaller .