How is Single Phase AC Different from Three Phase AC?
To begin with the simple, practical information, single phase AC power requires 3 wires: a hot, a neutral and a ground. Three phase requires 5 wires: 3 hots, a neutral and a ground. In three phase, each of the hot wires can complete a circuit with the neutral. Three phase power can carry more electrical capacity than single phase. Starting a 10 hp motor (starting a motor can require 6 times more power than running a motor) may cause a single phase line to blink or have a low voltage. A three phase line could allow that 10 hp motor to start without problem. Generally, three phase motors are more compact and efficient than similarly sized single phased motors, so the use of three phase motors is widespread. Large motors get used in so many applications: elevators, fans, blowers, compressors, pumps, conveyor drives, etc., so many projects require three phase electrical power. To understand three phase power, think about the 60 cycles of alternating current electricity, discussed above. Ea
