Types of the distribution system.
- Three phase three wire systems.
- Three phase four wire systems.
Three phase three wire systems
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This system requires 3 wires or conductors for distribution. Maybe connected in star or delta. If star connected then star point is connected to earth i.e. zero potential of 3 phase natural and balance i.e. magnitude of the current should be same in each phase an electrical load of single phase nature cannot be connected.
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Three-phase systems are used extensively. The 3-wire system may be delta-connected or star-connected whose star point is usually earthed.
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Basically, 3-wire 3-phase systems save one conductor, the neutral, in overhead construction.
In a service (600 volts and under) the source transformer winding is a delta or an open-delta. In California, if the voltage is 240V, then one of the corners is grounded. If it is 480V then it is ungrounded.
As a distribution system, the source transformer is typically a grounded wye winding and the neutral just is not extended outside the substation.
Three phase four wire system
Three phase four wire system
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This system requires 4 wire or conductor for distribution instar only, the star point is also called neutral an electric load of phase and signal phase can be connected.
Three phase four wire system
3 phase wire transmission \ 3 phase 4 wire utilization
Generated power is transmitted and distributed through.
- Overhead transmission lines.
- Undergrounded transmission cables.
