About 3 Phase Load Balancing

Visualizing Power

In EdgeManager, chargepoint current usage appears in Ampere or Kilowatts, with usage stacked in graphs. However, this obscures the complex reality that electricity delivers in 3 phases, each potentially carrying different loads.

Edge offers two visualization options:

Amps (A): Shows the HIGHEST of the 3 phases, since a fuse breaks when just one phase overloads. This reveals which vehicles use the highest grid load. However, this view can mislead when vehicles charge with 1-2 phases instead of 3, as graph areas appear identical despite different charging speeds.

Kilowatts (KW): Shows power accounting for all phases, ideal for displaying charging speed. However, it doesn't indicate whether power distributes across phases or concentrates on one.

3-Phase Visualization

A second visualization displays momentary phase usage by selecting "Current(+3 phase)," enabling a black vertical cursor revealing phase imbalance at specific moments.

Phase Imbalance and the Loadbalancer

Most electric vehicles use 3-phase charging, though some charge on 1-2 phases. When one EV charges at 16A on phase 1 (16, 0, 0) and another at 16A on phase 2 (0, 16, 0), the actual grid load remains 16A, despite the Amps view showing 32A.

Chargepoints with phase rotation often report current on incorrect phases due to misconfiguration. Therefore, by default Edge will assume the worst for the reported power usage of the chargepoints and take the worst reported current of a phase and apply it over all phases.

The Solution

Edge can only guarantee that the limits are not exceeded while loadbalancing with phase imbalance when it independently measures the power from the chargepoints with an energymeter.

When no energy meter exists, Edge takes each chargepoint's highest phase and applies that value across all 3 phases, guaranteeing safe operation.

For single energymeter installations at the main fuse, this approach provides convenience, safety, and near-optimal capacity use. However, the use of an energymeter is not required when the phase rotation in the chargepoints themselves is configured correctly. Contact LMS support to verify proper installation configuration.