Jeffrey Angus wrote:

On 1/29/2011 12:37 PM, Jamie wrote:

Yes, 2 phase of 90 degree's still exist, so why is that ok but 180
degree's isn't?

Because it's STILL a SINGLE phase across the transformer.

Look at power generators (portables), most of them have 2 circuits from
the generator 180 out from each other.. Why is this any different from a
generator of 90 degrees out ? You can combine a leg of each output from
a those generators also..

I serious doubt they make 90 Degree 2-phase generators.

As to combining multiple output windings from a SINGLE phase
generator, the output is STILL single phase.

It's argument that you won't win from those that truly understand the
meaning of phase angle supplies and the number of supply legs.

You're right, _YOU_ won't win that argument.

On combining multiple phases...

On more occasions than I care to recall, I've seen some poor
schmuck buy a 3-5 HP 240 VAC single phase motor, either on a
table saw or an air compressor, and have his "electrician
buddy" give him two of the 120 volt phases of the 3-phase
power in the shop to run his new equipment with.

Aside from the obvious, the voltage is 208 (Not 240), there's
a 120 phase difference between the two leads feeding the motor.
I usually get called in about 2-3 weeks on a "warranty request"
for said motor that just went up in flames.


I recently got a call about a pipe bending machine reporting low
voltage. Rated for 208 to 240 volts and was working fine a couple days
earlier, before it was moved to a new building. They insisted the
wiring was fine, and asked me to add a boost transformer. I did, and it
still didn't work. I finally convinced them to let me check the
voltage. I had 154 volts after the boost transformer, so i went to the
new three phase breaker box and found that someone like Jamie had wired
it. The black wire went to a single pole breaker, and the red went to
neutral. The business owner finally got hold of the company that did
the wiring, who insisted they did the job the right way. When they were
informed that they had used a single pole breaker, they called him a
liar but reluctantly agreed to send out a worker. Three hours later, he
shows up, admits they used the wrong breaker and promised to be back
'sometime next week'. After another couple calls, the owner of the
electrical business delivers the proper breaker. Guess who will ever be
called for any more work?

With 208 going to the boost transformer, I had 244 volts to the
machine. The operator's eyes went wide when he used it. He said it was
working about 50% faster, and bending at the speed it was supposed to.
It had never worked at full speed in the 10+ years they had owned it.

As far as the knuckle draggers:

You can buy single pole breakers.
You can buy double pole breakers.
You can buy three phase breakers.
--- BUT ---
You can't buy two phase breakers.


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.