Assume that a 120/240-V, 3-wire, single-phase
1 00-A panel board will be supplied from a 480-V servies
through a step-down transformer. Determine the mini
mum k VA rating of the transformer.
The transformer is single-phase, and the higher of the
two output voltages is used in the calculations. The k V,
is determined by using Equation 14.7.