100 Neutral Point.

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Section/Paragraph: 100 Neutral Point.

Added Text

Neutral Point. The common point on a wye-connection in a polyphase system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase portion of a 3-phase delta system, or a midpoint of a 3-wire, direct-current system. The grounded midpoint as described in Article 647 Sensitive Electronic Equipment is not a neutral point.

Substantiation:

Reduce possible confusion.

 

[don_resqcapt19]

It has to be a neutral point. 647.3 says the midpoint conductor is a grounded neutral conductor, and you can only have a neutral conductor if that conductor is connected to a neutral point.

 

[fmtjfw]

It has to be a neutral point. 647.3 says the midpoint conductor is a grounded neutral conductor, and you can only have a neutral conductor if that conductor is connected to a neutral point.

I believe 647.3 is in error when it states that the grounded midpoint is a neutral because it is not designed to carry current. The current carrying conductors are the two 60V from ground conductors connected each end of the isolation transformer's secondary winding.