Single-Phase power refers to a two-wire Alternating Current (AC) power circuit. Typically there is one power wire and one neutral wire. Those two wires produce AC power similarly to riding a bicycle, two legs are a single-phase system delivering power to your bike. With this system, the power is delivered unevenly, with maximum power when the legs are horizontal and no power when legs are at top and bottom.
Three-Phase power refers to three wire Alternating Current (AC) power circuits. Typically, there are three (Phase A, Phase B, Phase C) power wires (120 degrees apart in each phase) and one neutral wire. Three-Phase systems produce power similarly to riding a bicycle, but with an imaginable third leg and third pedal. It can deliver power continuously to the bike instead of delivering power unevenly as Single-Phase does. The major advantage to a Three-Phase system is that it delivers large power more efficiently, reliably, and smoothly.
In the United States, SANYO DENKI is providing mainly Single-Phase UPS (Uninterruptible Power Supply) systems. Please contact Sales for Three-Phase UPS systems.