"Chris Lewis" wrote in message
...
According to PrecisionMachinisT :


"Two phases from a three phase circuit" would better describe a circuit
connected to a three phase supply through three wires but having no load
across one of the phases.

"Two phases from a three phase circuit" is a single phase circuit. How
it's derived isn't really relevant at the point-of-use.

The confusion arises out of the word "phase".


Im not confused, someone else is confused about some apparent percieved
confusion--you just got caught in the crossfire is all.....

Technically, "three phase" describes the circuit itself. When you "take
two phases" from a three phase circuit, "take two phases" is slang
for what would have been more clearly said as "taking two of the three hot
conductors".

Hint: our shop has a single phase service at 400 amps, we buss 170 amps
of
this to generate our own three phase power via rotary transformer in
order
to supply the machinery.

What does that have to do with the situation at hand?

Absolutely nothing, except to demonstrate you can generate OR pick a single
phase and generate three phases from it.

Notwithstanding, I *will* concede that at most any modern commercial power
plant, three phases are generated......sheesh....pertty sure theres
generally three syncronous alternators upon a common shaft electrically
linked via a wye connection.....

Hell, I'm a machinist, myself and many others like me actually make the
damned equipment.........

If I look closely I can see bits *I* actually made in these photos :

http://www.transmission.bpa.gov/Plan...20Substati on

If Mr. Volts500 Sparkie0 dude can puff his chest and brag, then why cant *I*
?


At any rate, a better description IMO would have been something like "
a
two wire service, usually one phase of a three phase supply"

That's also correct, but doesn't imply (as perhaps it should) that the two
wires are hot wires. Not one of the hots and a neutral, for example.

Unless its corner grounded delta, or some other obscure and likely obsolete
transmission system, granted, no.

Point being, while it is one thing to have a specific service into a
facility, and then only purchase equipment that will easily integrate into
the existing plant electrical distribution, it is quite another to have the
knowledge and ability to interface equipment having different needs into an
existing system--480 v single phase can be easily supplied to most any
equipment.....pretty much regardless of the existing AC service, be it three
phase or single, so long as it is capable of handling the amperage draw of
the connected load.

Cheers,

--

SVL