On Tuesday 04 May 2004 00:19, der Mouse wrote:
> > 240V three-phase is a delta setup, with the neutral half-tapped
> > between two phases, giving 240V phase-to-phase, 120V
> > phase-to-neutral on two of the phases, and 208V phase-to-neutral on
> > the third one.
>
> That doesn't sound much like what I think of as neutral - ie,
> something that has zero nominal voltage to ground.
No, it is a neutral, because it is grounded. On a three-phase delta,
you ground the center tap of one (only one!) of the phases.
> Certainly if you have three phases 120? apart such that there is
> 240VRMS between any two phases, you can center-tap between any of two
> them, but the tap won't be 0V to ground and thus I would maintain
> that calling it "neutral" is misleading, enough so that I'd call it
> _dangerously_ misleading. (By my calculations, it will be something
> like 70V to ground, but I'm not sure I have the math straight.)
In all of my examples, the neutrals were "grounded neutrals". Maybe I
should have been more clear about that.
Pat
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Received on Tue May 04 2004 - 11:12:08 BST