Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

fault mva
fault megavolt-amps (mva) is the fault level expressed in terms of volt-amps rather than amps. One advantage of using volt-amps rather than amps is the same flow is experienced on both sides of a transformer when expressed in volt-amps, while the flow changes due to the transformer turns ratio when it is expressed in amps. Volt-amps for
a three-phase fault are expressed as 1.73 x rms line-line voltage x rms symmetrical fault current. Volt-amps for a single phase fault are defined as 1.73 x rms line-line voltage x rms symmetrical current in the faulted phase.