Actually the answer is quite simple: KVA is a Transformers safe Current rating for the Primary & Secondary voltages applied. Sample: 5KVA = 5K (5x1000) or 5000 Volt Amps. Volt Amps is a NEMA rating evaluating the (%) of Voltage Drop at the applied voltage specified for the transformer. The KVA rating will "safely" supply the specified voltage applied for your application.

5KVA at 480 Volts AC Primary - 120VAC Secondary is rated good for approximately 40 amps.

The Transformer will be pulling Approximately 10.5 amps at 480VAC - full load.

5KVA at 480 Volts AC Primary - 120VAC Secondary is rated good for approximately 40 amps.

The Transformer will be pulling Approximately 10.5 amps at 480VAC - full load.