what does a 3 phase mean?

Answer 1

In a three-phase system, three circuit conductors carry three alternating currents (of the same frequency) which reach their instantaneous peak values at different times. Taking one conductor as the reference, the other two currents are delayed in time by one-third and two-thirds of one cycle of the electrical current. This delay between "phases" has the effects of giving constant power transfer over each cycle of the current, and also makes it possible to produce a rotating magnetic field in an electric motor.

Answer 2

I don't know how much detail you want, but here goes...

When transmitting Alternating Current power, ie. AC power, the most common method used through out the world is 3 phase.

What this mean is that you have 4 wires at the beginning: 3 voltage wires, and 1 common (usually) or just 3 wires.

In the case of former, 3 generators are involved, and are connected one wire from each generator to one voltage wire, and the other wire to common. This is called the STAR or "Y" configuration. For reasons that is beyond this explanation, the common wire is not used for transmission.

In the case of later, between wire AB, BC, and CA, there is a generator. This is called the DELTA configuration.

Either way, each wire transmits A/C signal 120 degree out of phase from each other. Using 3 wires, you can transmit 3 different power. If you notice, you just saved ONE common wire. You can see, how this results in BIG savings for billions of miles of wire!

Anyway, this 3 phase transmission method is used for all major power transmission. It simply means 3 separate power transmissions, 120 degrees out of phase from each other, using only 3 wires.

DO NOT confuse this with 220 volt at home where there is a center wire to give you 110 volts. This is single phase.

This is nearly impossible to explain without being able to draw you a chart.

Answer 3

Essentially three separate AC voltages and currents, 120 degrees out of phase with each other, running in three separate conductors.
Each of the pairs carries 240VAC single phase, and any of the wires to a neutral will supply 120VAC.
The advantage is, that motors have much higher torque with three phases, as the power generated rotates with highest power pulses only 120 degrees apart (rather than 180 degrees as in single phase).

Answer 4

Actually, voltage between any two wires in three-phase power is 208VAC since each line is 120degrees out of phase, not 180degrees as in two-phase.

Two-phase power is standard in residences, while three-phase is rare. Three-phase is much more common in commercial and industrial settings.

Answer 5

accordinding to the people I work with . 3 phase means bundling wires together until the sparks fly or you trip a breaker.

Answer 6

This is how AC electrical wires run, with a + line, a - line and a ground. The voltage for this is 220 V, but you split off one power line and a ground for 120 V line, and use the 3 phase line for your big-ticket electrical appliances such as ovens and heat/air conditioning units.