The unipolar touch in a three-phase network with an isolated midpoint wire
In a network with an isolated neutral usually for simplicity of the analysis phase voltage U1, U2 believe, that, U3 resistance of isolation of wires concerning the ground г1, г2 are equal and symmetric, and, г3 are identical and equal гиз as shown in figure 3. Owing to full symmetry the potential of an average point concerning the ground is equal to zero (fig. 3á, 3в). Identical voltage of phases are enclosed to resistance of isolation. The touch of the person to one of phases (fig. 3б) creates a circuit of a current through a body of the person and isolation of other wires. The current through a body of the person will be equal
As resistance of isolation big enough the current through a body of the person will be small. In a three-phase network with an isolated neutral the person is under protection of resistance of isolation of a network.
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