Cor, you missed which connector I was talking about. It is the NEMA 10-50
that has the neutral connection not the J1772. It is the 10-50 that can be
wired to earth instead, and usually is when wired to the main panel, as they
are bonded together there. The equipment plugged into the 10-50 determines the
function of the center pin. Only dryers and stoves put any current into the
grounded pin, so this is a fully safe use, just not conforming to the NEMA
chart that labels the center pin of a 10-50 as neutral only. The NEMA 14-50 is
the more idiot proof and more universal for new equipment and specified for
RVs, but not required for EVs or welders as they don't use the neutral
connection.
Phil
On Saturday, February 14, 2026 at 09:19:24 AM EST, Cor van de Water via EV
<[email protected]> wrote:
No, J1772 does not have a "neutral" power connection. It is purely Earth,
the only power you can draw without immediately triggering GFCI is 208 or
240V phase+phase.
Cor.
On Sat, Feb 14, 2026, 8:09 AM DOOLEY PHILIP G JR via EV <[email protected]>
wrote:
> My point about the J1772 connector was completely misunderstood. What I
> tried to say is that the same type of pin in the J1772 was used for power
> and earth, unlike what is normal in NEMA 4 pin connectors where the earth
> pin is very different. This is to support that it should be fine to use
> the center pin of a 3 pin NEMA 10-50 for earth when it is not needed for
> neutral which is true for most 240V loads like charging an EV or running a
> welder. The US J1772 does not have a neutral because it is not needed.
> Always using a 4 pin NEMA connector for 3 wires helps to "idiot proof" the
> connections but costs more and is less durable.
> Everyone should remember that your house with its 120/240V loads is
> connected to the grid by 3 wires to save money and improve lightning
> protection. Phone/data lines and cable TV have to put up with significant
> common mode voltages as a result. In remote farms this voltage can kill
> the animals. Last I looked the code still allowed a 3 wire 120/240V
> connection to a shed if you put in a ground rod. This causes problems with
> Ethernet and cable TV putting excess current on the shield. My ground rods
> measure 500 to 1000 ohms because of ledge so I plan to always use 4 wire
> connections to my sheds.
> Phil
> On Friday, February 13, 2026 at 06:19:26 PM EST, Cor van de Water via
> EV <[email protected]> wrote:
>
> The J1772 is sometimes used by RV'ers to llug in, but requires a
> transformer (can be auto-transformer, meaning only 1 winding with center
> tap) to create a "Neutral" as long as it only connects to the 2 hots and
> keeps the new neutral separate from the ground wire.
>
> The proximity pin is not used in the cable in America, because the cable is
> permanently attached to the EVSE.
> So, in the US the only use of Proximity is to confirm secure plug in,
> before the vehicle is allowed to draw charge. As soon as you push the latch
> on the handle, the resistance in the handle changes and the car stops
> charging.
> In Europe the proximity carries a resistor in the cable you plug into the
> EVSE that tells what current the cable can support and the EVSE adjusts its
> advertised current via the Pilot signal to the minimum of cable and its own
> limitation.
> The car still reads the Proximity on the car side for the same function as
> in the USA.
> use of the car side Proximity signal by the EVSE is optional.
> Cor.
>
> On Fri, Feb 13, 2026, 8:32 PM (-Phil-) via EV <[email protected]> wrote:
>
> > I'm not aware of any EV or EVSE using the J1772 type 1 ground for
> neutral.
> > This violates the standard, and would (should) instantly trip the ground
> > fault detection in the EVSE and any upstream GFCIs.
> >
> > On the type 1 (US) connector there are only 5 pins; one ground connected
> > only to the vehicle chassis and serving as reference for the 2 small
> > proximity pilot (PP) and control pilot (CP) pins, and the 2 AC current
> > carrying pins. One of these will be neutral if using level 1 (120v).
> The
> > PP tells the EV a cable is connected and also the status of the
> mechanical
> > latch, and the CP tells the EV the supplied amperage and allows the EV to
> > enable AC power.
> >
> > On the EU spec type 2, they add an actual neutral and 1 more AC pin to
> > enable 3-phase with neutral.
> >
> > The combo spec adds 2 large DC only pins at the bottom for DCFC.
> >
> > Grounds by intended design are never supposed to carry current, they are
> > only used for fault handling, and to provide a return for leakage and
> > high-frequency RF.
> >
> > On Fri, Feb 13, 2026 at 10:23 AM EV List Lackey via EV <
> [email protected]>
> > wrote:
> >
> > > On 13 Feb 2026 at 7:15, DOOLEY PHILIP G JR via EV wrote:
> > >
> > > > using a neutral pin for earth might be a misuse, but the J1772
> > connector
> > > > does this.
> > >
> > > My first thought reading this was a bit of ignorant skepticism - why
> > would
> > > J1772 need a neutral pin?
> > >
> > > I've never used a J1772 personally, so I looked at the description
> here.
> > >
> > > http://evdl.org/docs/j1772description.pdf
> > >
> > > On the first diagram on page 2, titled J1772 Interface, I noticed 2
> extra
> > > pins, not shown as in use in the diagram on the first page.
> > >
> > > Page 3 has a full pinout for the connector. It does indeed illustrate
> 3
> > > large (presumably high current) pins. It describes them as mains,
> mains,
> > > and ground/neutral.
> > >
> > > Combining ground and neutral that way is reminiscent of the bad old
> days
> > > of
> > > US 3-pin 30 amp clothes dryer and 50 amp electric range connectors.
> It's
> > > very surprising that the J1772 designers thought that way.
> > >
> > > One more puzzle -
> > >
> > > In addition to the smaller pilot pin, there's a second smaller pin
> > > described
> > > as no connection.
> > >
> > > Now I wonder what that "no connection" pin might have been reserved for
> > in
> > > the original J1772 specification. Does anyone know the history?
> > >
> > > David Roden, EVDL moderator & general lackey
> > >
> > > To reach me, don't reply to this message; I won't get it. Use my
> > > offlist address here : http://evdl.org/help/index.html#supt
> > >
> > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> > >
> > > First they came for the journalists. We don't know what
> > > happened after that.
> > >
> > > -- Unknown
> > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> > >
> > > _______________________________________________
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