You have a three-phase one-line device that is not a panel or a meter center. It has multiple single-phase loads on it. All the loads start on phase A, resulting in a very unbalanced panel.
In the Circuiting dialog, change the Starting Phase for some of the circuits on the one-line device.
This works for:
- Bus Gutters / Bus Ducts
- Enclosed Breakers / Disconnects
- Motor Control Centers
- Transfer Switches
Why? (The Difference Between Panels and Switchboards)
The circuits on panels and meter centers rotate their starting phase automatically. Circuit 1 is on phase A, circuit 3 is on phase B, circuit 5 is on phase C, and so on. If you connect single-phase loads, they end up nicely balanced on the panel.
All other one-line devices, such as switchboards, do not rotate their starting phases. All circuits start on phase A. If you only use three-phase loads, this works fine and everything ends up balanced.
However, when you use single-phase loads, they all end up on phase A. You have to manually move some of the loads to a different phase to balance the panel.