Greetings,
I am trying to get as exact a measurement of power (W) as possible for a 280VAC-1Phase circuit feeding two power supplies in a load sharing configuration.
For the purposes of measurement I am using a pair of IEC320 power cables with outer insulation stripped away so I can use an inductive current meter on the individual phase wires. I wouldn't use such a cable in an everyday/production setting.
I have a single system with two load sharing power supplies (autoranging 120-240, 50-60Hz).
The two supplies are plugged to the same 280VAC-1Phase source (L1, L2, Ground).
I do not know how well tuned the phase shift between L1 and L2 are. IOW, I can only assume they are shifted 120 degrees.
Here are the readings I get when the system is under full load:
Power supply 1: L1=5.1A, L2=4.9A
Power supply 2: L1=5.0A, L2=4.9A
Since I can only measure one leg at a time and the load has minor fluctuations I am assuming that the L1 current draw is the same on both power supplies.
I have read up on this and I understand from Google searches and other topics on this forum that calculating 280V can be somewhat black magic.
So to get the closest to 280VAC-1Phase power consumption for this system would it be:
((120 * ((Ips1_l1 + Ips1_l2)/2) + (120 * ((Ips2_l1 + Ips2_l2)/2))
((208 * ((Ips1_l1 + Ips1_l2)/2) + (208 * ((Ips2_l1 + Ips2_l2)/2))
(208 * ((Ips1_l1 + Ips1_l2 + Ips2_l1 + Ips2_l2)/4))
or something entirely different?
If I look at each leg it appears I am pulling ~20A of 120V which would be 2400W. This is a much higher number than I was expecting and it is my impressions that running at 208VAC-1PH adds some efficiency and power savings. These numbers make me second guess everything which is why I am here.
Anyone willing to clear the air for me?
I am trying to get as exact a measurement of power (W) as possible for a 280VAC-1Phase circuit feeding two power supplies in a load sharing configuration.
For the purposes of measurement I am using a pair of IEC320 power cables with outer insulation stripped away so I can use an inductive current meter on the individual phase wires. I wouldn't use such a cable in an everyday/production setting.
I have a single system with two load sharing power supplies (autoranging 120-240, 50-60Hz).
The two supplies are plugged to the same 280VAC-1Phase source (L1, L2, Ground).
I do not know how well tuned the phase shift between L1 and L2 are. IOW, I can only assume they are shifted 120 degrees.
Here are the readings I get when the system is under full load:
Power supply 1: L1=5.1A, L2=4.9A
Power supply 2: L1=5.0A, L2=4.9A
Since I can only measure one leg at a time and the load has minor fluctuations I am assuming that the L1 current draw is the same on both power supplies.
I have read up on this and I understand from Google searches and other topics on this forum that calculating 280V can be somewhat black magic.
So to get the closest to 280VAC-1Phase power consumption for this system would it be:
((120 * ((Ips1_l1 + Ips1_l2)/2) + (120 * ((Ips2_l1 + Ips2_l2)/2))
((208 * ((Ips1_l1 + Ips1_l2)/2) + (208 * ((Ips2_l1 + Ips2_l2)/2))
(208 * ((Ips1_l1 + Ips1_l2 + Ips2_l1 + Ips2_l2)/4))
or something entirely different?
If I look at each leg it appears I am pulling ~20A of 120V which would be 2400W. This is a much higher number than I was expecting and it is my impressions that running at 208VAC-1PH adds some efficiency and power savings. These numbers make me second guess everything which is why I am here.
Anyone willing to clear the air for me?