Hi Gary,
I have had no personal experience with wiring a 2 phase system, but my
"American Electricians Handbook" Eleventh edition Page 3-10, Fig. 3-23, Fig
17 shows 2 phase, 4 wire as two separate single phase circuits 90 degrees of
phase apart. You are correct in that it does not call one of the conductors
in a single phase two wire circuit a "neutral" either (Fig. 14)
But in the diagram there is no "voltage relation" between the two pairs.
So possibly using the term "neutral" on my part was not technically correct
unless it is a accepted term to describe one of the conductors of a single
phase circuit. In either event it seems that you can switch a 2 phase, 4
wire, circuit with two poles as it would interrupt each of the pairs
satisfactorily.
After all the discussion fun as it is, of greater curiosity is why have
we have not heard a peep from Dan Miller, the original poster of the
question?
Helpfully
Alan

ps ( would you like to have a scan or fax of the chart?)

"Gary Coffman" wrote in message
There aren't any neutrals in a 4 wire 2 phase system. All 4 wires are hot.

Gary