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TonyWilliams
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Re: charging on generator

Sun May 20, 2012 12:47 pm

Interesting piece of the puzzle I missed.

Thanks.

smkettner
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Re: charging on generator

Sun May 20, 2012 9:30 pm

I have seen the same plug used with #14 copper connecting neutral and ground. No resistors.
1 bar lost at 21,451 miles, 16 months.
2 bar lost at 35,339 miles, 25 months.
LEAF traded at 45,400 miles for a RAV4-EV
RAV4 traded in for I-Pace Dec 2018

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hill
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Re: charging on generator

Mon May 21, 2012 5:03 am

rainnw wrote:
mitch672 wrote: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
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Re: charging on generator

Mon May 21, 2012 9:06 am

smkettner wrote: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.

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Ingineer
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Re: charging on generator

Mon May 21, 2012 3:15 pm

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
Easily Learn Electricity HERE! - - - - Website: http://evseupgrade.com/[/size] - - - - Like us on Facebook: EVSE Upgrade

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hill
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Re: charging on generator

Mon May 21, 2012 4:50 pm

QueenBee wrote:
smkettner wrote: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.
:D

smkettner
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Re: charging on generator

Sat Jun 02, 2012 5:01 pm

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.
1 bar lost at 21,451 miles, 16 months.
2 bar lost at 35,339 miles, 25 months.
LEAF traded at 45,400 miles for a RAV4-EV
RAV4 traded in for I-Pace Dec 2018

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Ingineer
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Re: charging on generator

Sat Jun 02, 2012 8:42 pm

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
Easily Learn Electricity HERE! - - - - Website: http://evseupgrade.com/[/size] - - - - Like us on Facebook: EVSE Upgrade

QueenBee
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Re: charging on generator

Mon Jun 11, 2012 8:55 am

Ingineer wrote: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?

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Ingineer
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Re: charging on generator

Mon Jun 11, 2012 10:15 am

QueenBee wrote:
Ingineer wrote: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)

Image

-Phil
Easily Learn Electricity HERE! - - - - Website: http://evseupgrade.com/[/size] - - - - Like us on Facebook: EVSE Upgrade

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