"Ralph Mowery" says...

Do you have single-phase or two-phase electric service?
No such thing as 2 phase



There is (was). What is split phase in most of the US is
mistakenly
called 2 phase by some. However there really is 2 phase.
I hop ewe don't have to go through the same old 400
postings about this.


Two-phase electrical power was an early 20th-century
polyphase
alternating current electric power distribution system.
Two circuits
were used, with voltage phases differing by one-quarter of
a cycle, 90°.
Usually circuits used four wires, two for each phase. Less
frequently,
three wires were used, with a common wire with a
larger-diameter
conductor. Some early two-phase generators had two
complete rotor and
field assemblies, with windings physically offset to
provide two-phase
power. The generators at Niagara Falls installed in 1895
were the
largest generators in the world at that time and were
two-phase
machines. Three-phase systems eventually replaced the
original two-phase
power systems for power transmission and utilization.
There remain few
two-phase distribution systems, with examples in
Philadelphia,
Pennsylvania; many buildings in Center City are
permanently wired for
two-phase[2] and Hartford, Connecticut.[3]

Thanks for explaining this, Ralph. ;)