wrote in message ...

On Sat, 25 Jun 2016 22:28:14 -0400, wrote:

On Sat, 25 Jun 2016 21:13:02 -0500, notX
wrote:

On 06/25/2016 06:01 PM, wrote:

[snip]

Sigh. Do we have to go through this all over again? A service
rated at 240V, 200A will support a load of 240V, 200A or a balanced
load of 120V, 400A. Yes the current in the service conductors
never exceeds 200A, but if you have 200A flowing through one leg
through 200A of 120V loads, through another 200A of 120V loads,
and then back out the other leg, it's handling 400A of 120V loads.

Dear Sir you look at it your way and I will look at it my way. have
nice day

The point is the neutral only handles the unbalanced load between the
2 ungrounded conductors and is they were both pulling equal amounts,
the current in the neutral is zero.


In other words there is 200A here (one ungrounded conductor) and 200A
there (the other ungrounded conductor) and 0A (the difference between
the two, never more than 200A) in the grounded conductor. NEVER 400A
anywhere.

Yes, on single phase that is true. On 3 phase wye, you can get triplin
harmonics that may have the neutral carrying more current that simple
math might predict. That happens with reactive loads like solid state
flourescent ballasts and PC power supplies. That would need to be the
main part of the load to become a problem.
and it would need to be a 3 phase panel - which would NOT be a 240
volt service. (It would be 208 in most cases)

That would be incorrect it could have 208, 220, 240, or 270 it all
depend on costumer setup, in most cases through out heavy industries
270 is standard but for Homers use it floats 208-240. Some chip
organization may use one leg of 480 for 240 & Neutral.
when you work with industrial people do not take anything for granted!