Awl--

Is this normal?

I know the wild leg has a higher *leg-to-leg* voltage than the non-generated
leg-to-leg voltages (the three leg-to-leg voltages measure 240 (incoming),
250, 265, approx), but wow, I thought *to ground* it might be 140 V or so,
but not a full 230!!!

W/ a good load on it, like a 1,000 watt heater, it drops to 195 V, but
damn!!!

Fortuitously, from my 3-phase panel, I did not connect any single (or double
pole) breakers to the wild leg, simply to lighten the load on the rotary,
but I was not aware of the above little ditty!!

Any thoughts?
----------------------------
Mr. P.V.'d
formerly Droll Troll

Careful, "Procto", you're going to keep fooling around with that volt meter
until you hurt yourself.

Bob Swinney
"Proctologically Violated©®" wrote in message
...
Awl--

Is this normal?

I know the wild leg has a higher *leg-to-leg* voltage than the
non-generated leg-to-leg voltages (the three leg-to-leg voltages measure
240 (incoming), 250, 265, approx), but wow, I thought *to ground* it might
be 140 V or so, but not a full 230!!!

W/ a good load on it, like a 1,000 watt heater, it drops to 195 V, but
damn!!!

Fortuitously, from my 3-phase panel, I did not connect any single (or
double pole) breakers to the wild leg, simply to lighten the load on the
rotary, but I was not aware of the above little ditty!!

Any thoughts?
----------------------------
Mr. P.V.'d
formerly Droll Troll

Yep, I calculate 231 V, So 230 Would be about right, assuming your
240 is a standard center ground 120/240 single phase system.
Do the math, it is a simple calculation.




"Proctologically Violated©®" wrote:

Awl--

Is this normal?

I know the wild leg has a higher *leg-to-leg* voltage than the non-generated
leg-to-leg voltages (the three leg-to-leg voltages measure 240 (incoming),
250, 265, approx), but wow, I thought *to ground* it might be 140 V or so,
but not a full 230!!!

W/ a good load on it, like a 1,000 watt heater, it drops to 195 V, but
damn!!!

Fortuitously, from my 3-phase panel, I did not connect any single (or double
pole) breakers to the wild leg, simply to lighten the load on the rotary,
but I was not aware of the above little ditty!!

Any thoughts?
----------------------------
Mr. P.V.'d
formerly Droll Troll


jk

jk wrote:
Yep, I calculate 231 V, So 230 Would be about right, assuming your
240 is a standard center ground 120/240 single phase system.
Do the math, it is a simple calculation.
Hmm, I come up with 208 V (207.846 actually)

The math is sin (60 degrees) * 240 V or

tan (60 degrees) * 120 V

both give 208 V.

This is the voltage from the center of the 240 V single phase source
(neutral) to the generated phase. But, it really isn't a useful
reading, as the motor never sees this voltage. All it sees are the L-L
voltages.

Jon

I learned the hard way that it don't work to have something running between
the wild leg and ground. Burned up the servo feed on my bridgeport. i didn't
know this was how it was wired, just hooked up the three phase and truned it
on. Now I know to spend serious time finding were to put the "wild" leg.

Karl

Jon Elson wrote:

jk wrote:
Yep, I calculate 231 V, So 230 Would be about right, assuming your
240 is a standard center ground 120/240 single phase system.
Do the math, it is a simple calculation.
Hmm, I come up with 208 V (207.846 actually)

The math is sin (60 degrees) * 240 V or

tan (60 degrees) * 120 V

both give 208 V.

This is the voltage from the center of the 240 V single phase source
(neutral) to the generated phase. But, it really isn't a useful
reading, as the motor never sees this voltage. All it sees are the L-L
voltages.

Jon

Nope.
IF! the voltage was 240 all the way around you would be correct.

Draw the triangle out. THe neutral point is the mid point of the 240 v
side. Approximate the 250-265 v as 260 V. THe N to "hot leg" voltage
is sqrt((260^2)-(120^2)).


jk