What Does Phase Mean in Three Phase Supply?

AI Thread Summary
Three-phase supply refers to a system where three wires carry alternating current, each separated by an angular difference of 120 degrees. This phase difference allows for a more efficient power transmission compared to three separate single-phase systems, which would require six wires. The concept of "phase" indicates the timing of the voltage waveforms on each wire relative to one another. By using a three-phase system, only four wires are needed: three for the phases and one neutral wire. This setup enhances efficiency and reduces material costs in power distribution.
ranju
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we talk about three phase supply .. I want to know that what actually is three phase..?? Its obvious there are three wires carrying current but what is "phase" ?
Is there something like, transmission line is further divided into three wires ..?? Please explain..its quite basic.. and I am confused..!
 
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ranju said:
we talk about three phase supply .. I want to know that what actually is three phase..?? Its obvious there are three wires carrying current but what is "phase" ?
Is there something like, transmission line is further divided into three wires ..?? Please explain..its quite basic.. and I am confused..!
You are right that it is quite basic and a simple Google search should turn up a good explanation with diagrams. Basically, it means exactly what it says ... there are three phases of voltages supplied, 120 degrees from each other.
 
ranju said:
we talk about three phase supply .. I want to know that what actually is three phase..?? Its obvious there are three wires carrying current but what is "phase" ?
Is there something like, transmission line is further divided into three wires ..?? Please explain..its quite basic.. and I am confused..!
the article above should help.
 
ranju said:
we talk about three phase supply .. I want to know that what actually is three phase..?? Its obvious there are three wires carrying current but what is "phase" ?
Is there something like, transmission line is further divided into three wires ..?? Please explain..its quite basic.. and I am confused..!

The phase means the angular difference between the sinusoidal voltage on one wire to another. For three phase, the angular difference would be 360/3 = 120 deg. Instead of having three independent single phase transmission system which require (phase + neutral wire for each phase) 2*3 = 6 wires, if we go for three phase system with angular displacement of 120 deg we need only (1 wire for each phase and 1 common neutral) 3+1 = 4 wires for the same power transmission.
 

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