RE: 3 phase pole pig (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 1 Nov 2007 23:39:21 -0500
From: sparks@xxxxxxxxxxxxxx
To: Tesla list <tesla@xxxxxxxxxx>
Subject: RE: 3 phase pole pig (fwd)

> I think the Yyn0 would be my choice. I don't know what a "zig
> zag" winding is.

A zig-zag winding is used to connect a 3-phase transformer or alternator
to produce a single phase output, for instance, 120-0-120 volts.  In
this configuration, all three windings are connected in series as
follows:

(120)-/\/\/\/\-(0)-/\/\/\/\--/\/\/\/\-(120)

winding = /\/\/\/\/

Due to the phase angle between windings, 120 volts is produced across
one winding, and the other two windings in series produce an opposite
polarity voltage which is the sum of their phase angles that result in
120 volts.

The zig-zag configuration allows the device to handle in single phase
operation about 60% of the total rated 3-phase power.

I have a nice 40 KW 3-phase alternator here that happily makes 27 KW
single phase in zig-zag connection.

73,

Ralph   W5JGV - WD2XSH/7