On Saturday, November 16, 2013 3:01:43 PM UTC-5, Danny D'Amico wrote:
On Sat, 16 Nov 2013 13:50:57 -0500, Wes Groleau wrote:



The reference is neutral. Each "hot" is 180º from the other when the

correct reference is used.



I had posted a detailed answer but it got lost since aioe is eating up

my posts, so, I'll reply again that I think they're 120 degrees out of

phase.



I replied to your original post explaining why you're wrong.




Here's why I think that.



The 3 wires on the street distribution line are all hot wires.

They come from a transformer (a whole series of them) which is wired

with three coils. Hence, they're each 120 degrees out of phase with

each other (Y or delta coils).



Then you take *two* of those hot wires, and send them into your house.

Those two are *still* 120 degrees out of phase (AFAIK).



That is where you're going wrong. You don't take two of the three
phase wires, you take ONE of them and put it through a center pole
step-down transformer. That gives you two hots and a center connection.
Between either hot and
the center connection you have 120V. Between the two hots you have
240V. The center tap becomes the neutral. If you look at the
waveforms of the two hots relative to the neutral, they are 180 deg
opposite each other.





You stick a neutral wire in between (which is just a wire to ground at

the poles) and now you have either two 120 volt circuits, or one three-wire

240 volt circuit.



The key point is that they're 120 degrees out of phase. I don't remember

the math, but that knocks the RMS (or whatever it's called) voltage to

something like 208 volts (but I don't remember the exact equation).



Anyway, since they're *not* 180 degrees out of phase, there will be

current in the neutral. Actually, I guess if the two hot wires are

not used for anything else, i.e., if they're a *dedicated* circuit,

I'm not sure if any current still goes into the neutral.



Per the above, all that is wrong.




Does anyone know if dryers are dedicated circuits?

Yes, at least every one I've ever seen.



If so, is there any current going into the neutral?



Again, as others have pointed out, the unbalanced portion
of the load current, which might be lights, timer, etc.
is flowing in the neutral




Note: If they were *not* dedicated circuits, then for sure there could

easily be current in the neutral since the loads wouldn't be balanced

all the time.

If a neutral is required for an appliance, then it should
always be assumed that current is flowing in it.