ssirobotics
Computer
- Jun 8, 2004
- 5
We have an industrial machinery that uses 208VAC 3 phase power (3 wire + Earth ground).
I need to figure out the Full load current and power consumption in KWatts to specify a UPS unit.
Each phase is fairly well balanced and draws about 7 Amps peak each during normal operation.
For extra margin I figure about 11 Amps Full load each phase.
To get the total Line current I did following:
Phase current * Sqrt(3) = Line current
11A * 1.732 = 19A
To calculate power consumption in kW I did following:
(Line current * VAC)/1000 = kVA
(19A * 208VAC)/1000 = 3.952 kVA
kVA * .7 = kW
3.952 kVA * .7 = 2.766 kW
I assume Full Load Current of a 3 Phase machinery is Line current and not phase current.
Can someone verify that this is correct?
I'm confused, since some UPS manufactures use following formula to figure out power consumption in kW:
(Full load current * Line VAC * 1.732 * .7)/1000 = kW
19A * 208VAC * 1.732 * .7)/1000 = 4.785 KW
I need to figure out the Full load current and power consumption in KWatts to specify a UPS unit.
Each phase is fairly well balanced and draws about 7 Amps peak each during normal operation.
For extra margin I figure about 11 Amps Full load each phase.
To get the total Line current I did following:
Phase current * Sqrt(3) = Line current
11A * 1.732 = 19A
To calculate power consumption in kW I did following:
(Line current * VAC)/1000 = kVA
(19A * 208VAC)/1000 = 3.952 kVA
kVA * .7 = kW
3.952 kVA * .7 = 2.766 kW
I assume Full Load Current of a 3 Phase machinery is Line current and not phase current.
Can someone verify that this is correct?
I'm confused, since some UPS manufactures use following formula to figure out power consumption in kW:
(Full load current * Line VAC * 1.732 * .7)/1000 = kW
19A * 208VAC * 1.732 * .7)/1000 = 4.785 KW