Supply Voltages

The primary operating voltage for most power electronics is divided into two general classes: low-voltage, service voltages of 600 V or less, and medium-voltage, service voltages of 601 V through 34.5 kV. The vast majority of power electronics will wind up on either 600 V-, 5-kV, or 15-kV-class supplies in the U.S., but there are applications at 2400 V and 6900 V, especially in older plants. Overseas, many other voltages may be encountered, with 400 V, 3300 V, and 11 kV being popular, all at 50 Hz.