charging on generator

[wwhitney]

The easy way to make this work is take a screw-on plug (NEMA 5-15P) and install two 1/2 watt 100k ohm resistors. One from neutral (silver screw) to ground (green), and the other from hot (gold screw) to ground (green). Then simply plug this into one outlet on the generator, and your EVSE into the other. This will safely pass the ground detect on the Nissan (and our upgraded) EVSE, while not being a hazard in any other way.

Why the resistor from hot to ground?

Thanks, Wayne

 

[MarkBC]

Just to bump this up the list, I also posted this question in the Engineering section. I got the Honda generator and need to modify the plugs to be able to charge the Leaf. I have learned that I need to connect the neutral and ground prongs for the EVSE GFCI check. However, it was mentioned that I need to connect via a 100,000 ohm resistor. Is this true?

The easy way to make this work is take a screw-on plug (NEMA 5-15P) and install two 1/2 watt 100k ohm resistors. One from neutral (silver screw) to ground (green), and the other from hot (gold screw) to ground (green). Then simply plug this into one outlet on the generator, and your EVSE into the other. This will safely pass the ground detect on the Nissan (and our upgraded) EVSE, while not being a hazard in any other way.

-Phil

Thanks, it worked! Unfortunately there seems to be only one electronics parts store in all of Vancouver, RP Electronics, and they are closed on Sunday. So I went to The Source and all they had was a 150 pack of assorted 1/4 W resistors which I bought. I used 180K ohm which should be fine at 1/4 W, and I only connected the ground to neutral, not the hot wire. I now have 149 extra assorted 1/4 W resistors...

Now I want to drive it out to the west coast to prove it can be done. I wrote a letter to Port Alberni to get them to put a Level 3 charger there because it is halfway between Nanaimo and the west coast, the perfect place for a zap. It hasn't been done yet, but in discussion apparently.

What I'll do one long weekend when I have the time (good luck finding time) is take the ferry over in the afternoon, then stop by Errington along the way where there is a Level 2 charger. I'll top off there for a few hours. Then I'll drive another 100 km until the battery dies, somewhere in the middle of nowhere, where I'll camp overnight and charge the car. Then in the morning I can finish the 100 km into Ucluelet. Not too bad of an inconvenience! And I will be the first person to ever drive an EV out to the West Coast.

 

[mitch672]

...I'll camp overnight and charge the car. Then in the morning I can finish the 100 km into Ucluelet

I think it might take longer than overnight @ 120V, 12A, more like 16-18 hours, no?

If you stop at an actual RV park/campground, and have a modified EVSE, you could plug it in to a "pedestal" (50A 240A outlet) and get a full charge overnight, no generator required.

 

[garygid]

Caution: If you drive until it stops, you might not be able to get safely off the road, and unlikely to be anywhere near a place where you can camp and run a generator.

Even if you carry enough gas to refuel your generator every few hours, most places will not let you run it during their night time "quiet" hours.

 

[MarkBC]

12 hours charge should be good, I don't run it totally dry and I don't charge it all the way since you seem to lose lots of charge quickly when fully charged anyways.

I'll be camping in the middle of nowhere so there won't be any "quiet time"...

Of course, if Nissan made a genset trailer that would solve ALL these issues!

 

[TonyWilliams]

12 hours charge should be good, I don't run it totally dry and I don't charge it all the way since you seem to lose lots of charge quickly when fully charged anyways.

It doesn't use the energy at any greater or lesser rate, except for extreme temperatures where the power is limited, and when the battery is almost empty, in "Turtle" mode, when again, the power is limited.

Obviously, limited power will use less than normal. But it won't use more, unless you ask for more energy use (turn on the heater, stomp on the gas pedal, turn on the lights, etc).

Please don't make decisions based on inaccurate info. If you need the range, charge the car to 100%. Just don't leave the car sitting for extended periods at 100%.

 

[Ingineer]

Why the resistor from hot to ground?

Thanks, Wayne

Keep in mind, on a isolated generator, there is no real "hot". The resistor puts the apparent ground right in the middle (+/-60v RMS), which is safer than arbitrarily designating one as hot. 100k is more than enough to pass the ground check, but will not pass enough current to be dangerous, and in fact, probably can't even be felt through most people's bare skin.

I still recommend two 1/2w resistors for safety, as I've seen 1/4w's fail to lower resistance at 120v. They are also more rugged.

-Phil

 

[dgpcolorado]

The easy way to make this work is take a screw-on plug (NEMA 5-15P) and install two 1/2 watt 100k ohm resistors. One from neutral (silver screw) to ground (green), and the other from hot (gold screw) to ground (green). Then simply plug this into one outlet on the generator, and your EVSE into the other. This will safely pass the ground detect on the Nissan (and our upgraded) EVSE, while not being a hazard in any other way.

-Phil

Why the resistor from hot to ground?

Thanks, Wayne

Keep in mind, on a isolated generator, there is no real "hot". The resistor puts the apparent ground right in the middle (+/-60v RMS), which is safer than arbitrarily designating one as hot. 100k is more than enough to pass the ground check, but will not pass enough current to be dangerous, and in fact, probably can't even be felt through most people's bare skin.

I still recommend two 1/2w resistors for safety, as I've seen 1/4w's fail to lower resistance at 120v. They are also more rugged.

-Phil

Thanks for the info. I gave this a try and it works fine. Working through Ohm's Law, the current through the resistors should be about 1.2 mA, 0.14 W, a tiny amount and well within the limits of the ½ Watt resistors.

I took advantage of a sale on the Honda EU2000i at the local farm and ranch supply store. Got the resistors from Radio Shack and the plug from Home Depot:

120 Volts is a very slow way to charge but it should help me extend my range limits somewhat. I figure that if the cities in my area ever do install L2 public charging I can always sell the generator on Craig's List; they are very popular with RVers.

 

[TonyWilliams]

Can somebody please confirm that there won't be a problem with this resistor plug setup for non-generator use?

 

[dgpcolorado]

Can somebody please confirm that there won't be a problem with this resistor plug setup for non-generator use?

:?: The grounding plug for generator use is separate from the EVSE. It just goes into the second outlet on the generator. Doesn't have anything to do with modifying the EVSE. Or am I missing what you're asking?

 

[TonyWilliams]

Interesting piece of the puzzle I missed.

Thanks.

 

[smkettner]

I have seen the same plug used with #14 copper connecting neutral and ground. No resistors.

 

[hill]

Hmmm, well just because you CAN do this, you think it's a good idea? Your putting out a lot of pollution with these low cost generators, kind of defeating the entire purpose of the Leaf.

Just Sayin...

The efficiency is around 25mpg, and probably less polluting than having to be flat-bedded out.

That'd be a pretty low number you're working with ... maybe around 2 mile per kWh. I ran 2 gallons througn our EU6500 (240v ... which is more efficient, too) and my mpg worked out to 35mpg.

 

[QueenBee]

I have seen the same plug used with #14 copper connecting neutral and ground. No resistors.

Phil says this is unsafe and doesn't want anyone doing it. I don't fully understand why and there seems to be some disagreement with OSHA regarding safe use of generators and grounding/neutral bonding but I trust that Phil knows what he is talking about so I switched to the resistor method.

 

[Ingineer]

I can think of many possible scenarios where a hard bond would create a dangerous situation, which in all cases, the resistor solution eliminates. It's not costly or difficult to implement, so I don't see why anyone would want to avoid it and go with a more dangerous direct bond.

Basically, if you have no solid ground reference, you should not bond anything. If you are willing to drive an 8 foot copper ground rod, then a hard bond is ok. If you are not willing to do this, then you should not create a hard bond capable of passing lethal current.

-Phil

 

[hill]

I have seen the same plug used with #14 copper connecting neutral and ground. No resistors.

Phil says this is unsafe and doesn't want anyone doing it. I don't fully understand why and there seems to be some disagreement with OSHA regarding safe use of generators and grounding/neutral bonding but I trust that Phil knows what he is talking about so I switched to the resistor method.

I didn't switch . . . I inquired - and 'resistor'd' my evse from the get-go.

 

[smkettner]

I got my pack of 110k ohm 1w resistors and the plug today.
Works just as expected.

I find it odd the Nissan evse fault light does not illuminate. Ready light just blinks without the bonding plug.
Probably in the manual somewhere

Generator is Kipor KGE3000Ti 2300va rated, 2600va surge. 120v. Works fine with econo-throttle on.

No real intention to use the generator. I just like to know it works if needed.

 

[Ingineer]

When the EVSE blinks the power light, it's letting you know that it cannot find a valid ground path. This is a built-in safety check, and without this test being passed, the EVSE will refuse to allow charging.

Since with a generator, there is no true "ground" as referenced by the earth, unless you drive a copper ground rod and properly bond it. The high-value resistors provide a balanced middle ground which will still safely pass small amounts of static and RF signals back to the body of the Leaf where they should be without providing a hazard where by a fault could cause deadly current to be available on the body of the Leaf and/or the Generator. The 100k resistors will not allow enough current to pass to present an electrocution danger to anyone, and it splits the difference so the maximum possible voltage potential over the floating ground is only about 60 volts at any time.

This is safe while still satisfying the EVSE's ground verification test.

Doing a hard bond without the resistors would now FORCE the body of the Leaf and the generator to be hard-connected to one side of the AC line, so in the event of a fault or alternate path, it could pass lethal electrocution current into a person. Keep in mind without driving the ground rod there is no effective neutral, as there is no reference to ground. Both power lines are effectively floating until you make a bond. This is known as "isolated ground" and would be fine, except the EVSE will not approve, and it also presents a hazard of damage to any of the connected systems by static and/or RF energy build up with respect to ground. If the static charge builds up and jumps into a nearby conductor, this sudden current could damage a component, such as the multi-kilobuck on-board charger module in the Leaf, the EVSE, or one of the generators system, such as it's automatic voltage regulator.

-Phil

-Phil

 

[QueenBee]

The easy way to make this work is take a screw-on plug (NEMA 5-15P) and install two 1/2 watt 100k ohm resistors. One from neutral (silver screw) to ground (green), and the other from hot (gold screw) to ground (green). Then simply plug this into one outlet on the generator, and your EVSE into the other. This will safely pass the ground detect on the Nissan (and our upgraded) EVSE, while not being a hazard in any other way.

Hey Phil, just thought of something. If charging from a 240 volt generator would it be beneficial to connect both hot legs and the neutral to ground via the resistors?

 

[Ingineer]

The easy way to make this work is take a screw-on plug (NEMA 5-15P) and install two 1/2 watt 100k ohm resistors. One from neutral (silver screw) to ground (green), and the other from hot (gold screw) to ground (green). Then simply plug this into one outlet on the generator, and your EVSE into the other. This will safely pass the ground detect on the Nissan (and our upgraded) EVSE, while not being a hazard in any other way.

Hey Phil, just thought of something. If charging from a 240 volt generator would it be beneficial to connect both hot legs and the neutral to ground via the resistors?

Yes, this is 100% correct. Then earth is then properly floating is in the "middle". This is also how we advise our European customers who have isolated grounds. (some places in Europe do)

-Phil