Nissan L1 EVSE third-party upgrade to both 120V and 240V

[Ingineer]

Signaling the EVSE to switch modes using the e-nozzle is a workable idea, but apparently some people have trouble just getting the J1772 plug to connect to their vehicle fully.

If one used the nozzle-release button (with the 2 small pins jumpered) to signal the EVSE to change Max-Amps, for better safety the EVSE should probably be modified to detect the no-diode condition so that the 120/240v AC is not delivered to the nozzle while "signaling".

Gary, if you'll note my previous posts about the EVSE, it will not allow power with a short or low resistance such as the release interlock. (it sees 150 ohms with the paperclip shunting the 2 small pins and then 480 ohms when the release is pressed, so my firmware would interpret this is "programming mode".)

Also, If I do alter the firmware, I'm going to at least get it closer to the standard. I probably can't do anything about diode detection as they haven't implemented a -12v supply and drive.

-Phil

 

[Ingineer]

A proper 15A circuit will withstand 15A indefinitely, which is why it's called a 15A circuit.

That is not correct for standard circuit breakers, which include all residential circuit breakers. Loading at 100% for an extended period may trip the thermal mechanism. It is designed to hold indefinitely at 80% load or for at least 3 hours at 100% load, at an ambient temperature of 40C. So in practice it may hold indefinitely at higher loads for a typical ambient temperature, but there is no guarantee. Anything designed as a continuous load (over 3 hours) should only use 80% of the circuit ampacity.

Yours, Wayne

I disagree. Here is a NEMA trip curve:

In any event, The "at least 3 hours" is essentially forever as by that time the thermal dynamics would reach equilibrium, right? The chart shows it flattening out at only about 15 seconds.

 

[garygid]

Perhaps this trip curve does not apply to all (possibly older) residential circuit breakers?

 

[Ingineer]

Perhaps this trip curve does not apply to all (possibly older) residential circuit breakers?

Possibly. This is why I decided to program the firmware to default to 12A if it loses power! =)

 

[garygid]

I agree that 12A is the best (safest) power-on default.

 

[wwhitney]

I disagree.

See (2008) NEC 210.20(A), 210.21(B)(2) and 210.23(A)(1), available here:

http://bulk.resource.org/codes.gov/bsc.ca.gov/gov.ca.bsc.2010.03.html#p70-49

The chart shows it flattening out at only about 15 seconds.

I'm not sure what you mean? That's not what I'm reading from the chart.

Cheers, Wayne

 

[LEAFer]

A downside of using the J-plug release button to "signal" higher current ... you are start-/stop-ing the charge cycle on the LEAF, and that also includes superfluous CarWings notifies of start/stop charging.

 

[Ingineer]

The chart shows it flattening out at only about 15 seconds.

I'm not sure what you mean? That's not what I'm reading from the chart.

Cheers, Wayne

Sorry, I meant 15 minutes. (900 seconds)

 

[Ingineer]

A downside of using the J-plug release button to "signal" higher current ... you are start-/stop-ing the charge cycle on the LEAF, and that also includes superfluous CarWings notifies of start/stop charging.

No, this would not happen, because all I have to do is delay that charge start a few seconds which gives you time to cycle the mode. (I mentioned this in the previous post.)

 

[LEAFer]

A downside of using the J-plug release button to "signal" higher current ... you are start-/stop-ing the charge cycle on the LEAF, and that also includes superfluous CarWings notifies of start/stop charging.

No, this would not happen, because all I have to do is delay that charge start a few seconds which gives you time to cycle the mode. (I mentioned this in the previous post.)

Excellent ! That would be nice. Thanks for thinking ahead (of me) And you're also saying the car will not mind the "cycling" of the proximity signal ?

 

[Spies]

I think 12A, 15A, and 20A make the most sense to offer. I don't see the point of a 16A mode.

If it was up to me I would make it 12A, 16A and 20A. My reasoning is this would allow one to stay within the 125% rule or 80% rule depending on how you look at it and also stay within the 20A rating of the cord set. So 12A would be for 15A circuits, 16A would be for 20A circuits and 20A would be for circuits 25A and above.

Having the unit default to 12A and cycle up through 16A and 20A using the release button sounds brilliant in theory and I look forward to hearing how it works in practice. I can hardly wait

 

[garygid]

Spies,
I agree.

However, for the release button scheme to work (without using a jumper on the J1772 plug before attaching it to the car), the car would need to respond to "Proximity" loss (press of the Release button) by changing the load on the Control Pilot, and the car's only options are 6v and 9v. It is not clear that the car would go into the "Charging" (6v) mode, so the 9v would not change, and ... no button-press feedback to the EVSE.

So, apparently are you planning on using the "manually inserted jumper" method to change the Max-Amps setting, right?

 

[EVDRIVER]

It should also have selectable charge tones that can be downloaded!

 

[garygid]

And you wonder why novices cannot tell when you are joking?

 

[DarkStar]

However, for the release button scheme to work (without using a jumper on the J1772 plug before attaching it to the car), the car would need to respond to "Proximity" loss (press of the Release button) by changing the load on the Control Pilot, and the car's only options are 6v and 9v. It is not clear that the car would go into the "Charging" (6v) mode, so the 9v would not change, and ... no button-press feedback to the EVSE.

Not necessarily. The specification allows the EVSE to read the status of the proximity pin. If you plug it into the car and then "clicked" the release button a couple of times, it would be fairly trivial for the EVSE to read it.

 

[garygid]

Normally the Proximity pin is not even connected to the EVSE, and the cable (e-hose) is only 4 wires.

 

[DaveEV]

A portable "plug in" load is not affected by this rule specifically. Take this 1800 watt space heater as example, they sell these as plug-in units which pull 15A but have standard NEMA 5-15 plugs on them which will be used on 15A circuits, and a heater is definitely a continuous load.

That appears to be a UK product - and the UK runs off 240V 50Hz so that heater is only a 7.5A load. No idea what the standards are in the UK. I've never seen more than a 1500W 120V rated space heater for sale in the US - 12.5A.

 

[garygid]

Also, UK breakers are different, AND some houses just have a main breaker, and each 240v appliance has a fuse built into its own cord's plug.

 

[downeykp]

Ok, so? I have been following this thread for some time now. Is this product going to be supplied or not?
If it is, we will need a price and will it really work. You engineer types are killing me with all of this technical
jargon.

 

[fotajoye]

Have an idea: why don't you create a separate 240v/16 amp portable unit that plugs into the twist loc 240v instead of a multi-input device. I think as I remember the circuit consist of a PWM, a relay (or semiconductor switch), diode and voltage divider to create the necessary 6 and 9 volt pilot. I think the J1772 plug is about $180 in bulk. If you sell it as a kit with UL parts, you can escape the liability. If you want to include ring tones have at it.