Balancing power panel loads

Use this information to ensure that power panel loads are balanced.

System configurations using three or four BPRs presents a balanced load to the utility, provided that both line cords are energized. When only one line cord is energized, systems drawing more than 24 kW will present a slightly unbalanced load to the utility. AC systems with two BPRs are unbalanced.

The following figure is an example of feeding several loads from two power panels in a way that balances the load among the three-phases.

Figure 1. Power panel load balancing

The method illustrated in the previous figure requires that the connection from the three poles of each breaker to the three-phase pins of a connector be varied. Some electricians might prefer to maintain a consistent wiring sequence from the breakers to the connectors.

The following figure shows a way to balance the load without changing the wiring on the output of any breakers. The three-pole breakers are alternated with single-pole breakers so that the three-pole breakers do not all begin on phase A.

Figure 2. Power panel load balancing

The following figure shows another way of distributing the unbalanced load evenly. In this case, the three-pole breakers are alternated with two-pole breakers.

Figure 3. Power panel load balancing