What are the distinctions in between a 3-phase 3-wire and a 3-phase 4-wire ...

3 Phase 3 wire system consists of all the stages i.e R Y and B while in 3 stage 4 wire system an extra neutral N exists. 4 wire system is generally utilized in circulation side to transform the 3 stage system into single stage to provide single stage family loads, where the neutral serve as the present return path.It is done by linking the secondary side of the circulation transformer in star.
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