3-Phase Load Balancer.

Three-phase power supplies three live legs (called L1, L2 and L3) that each carry the same voltage but peak at different times, so a single supply can deliver far more total power than a normal single-phase outlet. Events use it because PA, lighting rigs, LED walls and catering can pull tens of kilowatts, which is more than one 10 amp or 15 amp single-phase circuit can handle. In Australia each leg sits at about 230 volts to neutral, and the three legs together give roughly 400 volts between phases.

Balancing means spreading your gear so that L1, L2 and L3 each draw a similar number of amps, rather than piling everything onto one leg. If one phase is heavily loaded while the others sit idle, that leg can trip its breaker or overload its cable while the supply still has spare capacity elsewhere. As a rough rule of thumb, aim to keep your imbalance under about 10 to 15 percent so no single leg is doing most of the work.

For single-phase gear, divide the power in watts by the voltage, so a 2300 watt load on a 230 volt leg draws about 10 amps. Add up the amps on each phase and check the total stays comfortably under the rating of your distro outlets and the breaker feeding them. Always leave headroom rather than loading a circuit right to its limit, because motors, moving lights and amplifiers can spike well above their steady draw at switch-on.

When the three legs are evenly loaded the currents largely cancel in the shared neutral, so very little flows back through it. The more unbalanced your load, the more current the neutral has to carry, which is another reason to spread gear evenly. This is part of why a balanced rig is safer and runs cooler, and why the neutral and earth on event distros must be correctly rated and connected.

Yes. Plugging into existing three-phase outlets with the correct rated leads is normal crew work, but any tie-in to mains, switchboards or a generator's terminals must be done by a licensed electrician under Australian rules. This tool helps you plan your loads and check balance before the show, but it does not replace a qualified electrician signing off the actual connection.