Thanks for your insight.  Yes, the breaker will be 20 amps so if anyone
tries to do anything other than a single L2 or two L1's they will loose
both as the breaker will trip.  I do assume that a 20A 2 pole breaker
actually will trip based on an overload on either of the two sides
independently of what is on the other.


On Sun, Feb 17, 2019 at 7:32 PM Jay Summet via EV <> wrote:

> > I install two 120v outlets on each post along with a single 240v outlet.
> > And then a small note says, "Either one L2 or two L1's but not both".
> > Each post has properly rated #10 conductors for the 16 amps on Line1 and
> > Line2 and Ground and a #12 for Neutral since the Neutral carries either
> > zero or only the 12 amps of a single L1.
> >
> >
> > Is this legal under the NEC?
> It depends entirely upon your breaker size. As long as you don't have a
> breaker larger than 20 amps on either phase you should be good to go.
> I'm worried about you sizing the neutral smaller than the hots, as
> somebody may see the 10 AWG hot line and put a 30 amp breaker on it, not
> realizing the neutral wire still needs to be limited to 20 amps.
> I'm also worried about the ability for somebody to overload one of your
> hots by plugging into both the L2 and an L1 at the same time.
> A polite sign isn't the same as an interlock. You must assume some bozo
> will plug into the L2 and both L1's at the same time.
> (I assume the two 120v L1 outlets are on opposite phases of a split
> phase 240 setup for the 240v outlet.)
> For example, if somebody sets up a space heater that draws 15 amps on
> one of the L1 outlets, and then somebody else starts to charge their car
> at 16 amps on the 240 outlet, the total number of amps on one of your
> hots would be 31 amps, which is more than should be going over a 10 AWG
> wire.  If you had a 20 amp breaker no problem.  If you are using a 30
> amp breaker, no problem for the 240 volt circuit, but somebody could
> successfully draw 25 amps over your 10 AWG neutral if they (for example)
> had a 30 amp 120v RV circuit going through a 15 amp plug adapter.
> So either the breaker must trip because it's a 20 amp, or all the wires
> including the neutral must be sized to accommodate the full possible
> load, 10AWG for a 30 amp breaker.
> Jay
> _______________________________________________
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