Electronic – the current limit on each phase of a 160 kVA three-phase UPS

three phaseups

I'm a physicist by training, so I think I understand voltage, current, phase and power. However, I lack the knowledge to translate between this and the published ratings on three-phase electrical equipment.

If a three-phase UPS is rated at 160 kVA, does this mean that each phase can deliver 160/3 = 53.3 kVA? Or is there a factor of \$\sqrt{3}\$ involved?

Best Answer

Yes, a 3 phase 160kVA supply would mean 3 single phases each at 53.3kVA.

The factor of \$\sqrt{3}\$ arises in the power calculations when using a line-line voltage.

Note that the UPS may or may not be able to support unbalanced loads.