I have an installation where the customer wants to use a 480 D / 240V D transformer which i haven't dealt with that much. I have a bunch of loads that are 7000VA and will be fed with 2wire+gnd circuits (hot,hot,gnd) to be run off 230V.
I am looking at the calculation to balance the loads across all three phases and seem to be running into problems. It seems like the current should be
I= VAline/(sqr(3)*Eline) which gives me 17.6 amps. I think this is what you would see at the load possibly but when balancing the system, you would end up with your VA higher. I think then it works out like below because it is a 3phase system.
If you think about it say in a panelboard (in VA with three loads):
A B C
3500 A
3500 B
3500 C
3500 A
3500 B
3500 C
----------------------
7000 7000 7000
to amps
A B C
15.2 A
15.2 B
15.2 C
15.2 A
15.2 B
15.2 C
----------------------
30.4 30.4 30.4
It seems like I may be missing something but all of my numbers seem to work out except I am a bit leary on the first number of 17.4. Just looking for someone either to confirm this is correct, or show me the error of my ways.
I am looking at the calculation to balance the loads across all three phases and seem to be running into problems. It seems like the current should be
I= VAline/(sqr(3)*Eline) which gives me 17.6 amps. I think this is what you would see at the load possibly but when balancing the system, you would end up with your VA higher. I think then it works out like below because it is a 3phase system.
If you think about it say in a panelboard (in VA with three loads):
A B C
3500 A
3500 B
3500 C
3500 A
3500 B
3500 C
----------------------
7000 7000 7000
to amps
A B C
15.2 A
15.2 B
15.2 C
15.2 A
15.2 B
15.2 C
----------------------
30.4 30.4 30.4
It seems like I may be missing something but all of my numbers seem to work out except I am a bit leary on the first number of 17.4. Just looking for someone either to confirm this is correct, or show me the error of my ways.