Incorporating a Lightning into an existing PV system - without HIS

[world2steven]

The Sol Ark *will* work with the Lightning on the Gen input so long as the Ground Pin is removed from the cable plug in from the truck.

Thanks!! I will pass this along to Sol Ark tomorrow.

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[world2steven]

Thanks!! I will pass this along to Sol Ark tomorrow.

The next task is to get this approach approved by both Ford and Sol Ark.

 

[Maquis]

More conversation with Sol Ark. I mentioned "Neutral Switching" transfer switches like the Generac 9854 (50A) His reply was: "We're needing to confirm if this switch is just switching the neutrals? Or is it switching both the neutrals and the grounds?" If both, there may be a possibility connecting to the Sol Ark's 'gen' breaker would work.

It would be nice to come up with a generic solution, assuming this neutral-bonded / GFCI is a problem for all or most hybrid inverters - and then get it blessed by Ford. Ford's ties to Sunrun are sinking a powerful marketing pitch: 'a free truck and 10 Tesla Powerwalls for half (maybe now 2/3rds?) the price'

“Switching grounds” isn’t done….ever. The fact they mention this is troubling.

 

[world2steven]

“Switching grounds” isn’t done….ever. The fact they mention this is troubling.

The guy was going to pass this along to Sol Ark's CTO. (Hope he doesn't get fired! He was just trying to help.) Anyhow, what about
eopiela's suggestion:
"The Sol Ark *will* work with the Lightning on the Gen input so long as the Ground Pin is removed from the cable plug in from the truck."

 

[Maquis]

The guy was going to pass this along to Sol Ark's CTO. (Hope he doesn't get fired! He was just trying to help.) Anyhow, what about
eopiela's suggestion:
"The Sol Ark *will* work with the Lightning on the Gen input so long as the Ground Pin is removed from the cable plug in from the truck."

That will stop the truck’s GFCI from tripping. I don’t know enough about SolArk to know if will function properly.

 

[Yellow Buddy]

I met with an electrician for a site survey this week as well. He was similarly pessimistic about my ability to connect my home to the Lightning using a transfer switch or double-throw safety switch. He agreed with others here that if it were possible, the transfer switch would have to be installed completely independent of my solar array, solar inverter, Tesla Powerwall batteries, and Tesla Gateway.

He mentioned that a better approach would probably be to wait for new inverter technology to become available that allows a generator to be connected directly to the solar inverter and thus integrated into a solar power system. My impression is that this is what Sol-Ark is trying to do, but I'm not sure since I don't know much about them. Is any other inverter company (Enphase?) planning to release new inverter technology that would allow power input from a generator (or Lightning)?

SMA.

The Sunny Island allows direct generator integration and control. It can recharge your battery bank through generator, grid, or solar.

 

[world2steven]

For anyone who has a grid that doesn’t go down for days or weeks at a time, a Home Integration System doesn’t make sense, particularly those of us with solar and battery backup. It would be nice, however, to be able to use the Lightning’s battery in the event of an extended outage. Could this be accomplished with a manual transfer switch that would transfer the power source for a home grid from a hybrid inverter to a line connecting to the Lightning’s 240v port?

I discussed eopiela's suggestion -

"The Sol Ark *will* work with the Lightning on the Gen input so long as the Ground Pin is removed from the cable plug in from the truck. "

for connecting the Lightning to my inverter's generator port with Sol Ark this morning. Sol Ark's reply was that it should work if Ford doesn't have any problems with it.

Could this also be the answer for anyone just wanting to hook up to a critical loads panel via a manual transfer switch?

 

[Maquis]

Could this also be the answer for anyone just wanting to hook up to a critical loads panel via a manual transfer switch?

The best manual transfer switch solution is to buy the correct transfer switch that switches the neutral.

Others have previously reported success using the ground pin hack.

 

[world2steven]

Others have previously reported success using the ground pin hack.

Was that with feeding power to the generator port of a hybrid inverter? If so, I would appreciate links if you have them.

 

[Maquis]

Was that with feeding power to the generator port of a hybrid inverter? If so, I would appreciate links if you have them.

No - it was transfer switch - which is why I only quoted the part of your post the referred to a transfer switch. Sorry for the mixup.

 

[ridgebackpilot]

I'd venture to guess that removing the ground pin from the cable connection to the truck would allow virtually any transfer switch or hybrid inverter plug-in to work!

But as @Maquis has pointed out, that approach isn't a solution but rather simply a workaround, and not the safest at that.

 

[world2steven]

But as @Maquis has pointed out, that approach isn't a solution but rather simply a workaround, and not the safest at that.

What is the safety issue with removing the ground pin from the cable connection to the truck? Is it safer to use a transfer switch? If so, what kind? For those of us with a hybrid inverter with a generator port a transfer switch would seem overkill. Does removing the ground pin just keep the Lightning from faulting? If all components in a circuit had correctly bonded grounds wouldn’t current in their circuits just go to their grounds?

 

[world2steven]

correctly bonded grounds? I think I should have said neutrals.

 

[v2h8484]

What is the safety issue with removing the ground pin from the cable connection to the truck? Is it safer to use a transfer switch? If so, what kind? For those of us with a hybrid inverter with a generator port a transfer switch would seem overkill. Does removing the ground pin just keep the Lightning from faulting? If all components in a circuit had correctly bonded grounds wouldn’t current in their circuits just go to their grounds?

It's incrementally safer to use a transfer switch as the EV will be connected to true earth ground. You should just go ahead and try it either way. Make a video of it if you can. I am pretty sure you can't do any worse than this guy who is clearly clueless about grid-tied solar:

 

[world2steven]

I am having trouble putting all this together.

This is from the Sol Ark 12 owner’s manual:
The system must have Ground connections and Neutral connections. Ground MUST be bonded to Neutral ONLY ONCE in the circuit.

And this is from the Lightning manual:
Grounding Type
Neutral Bonded

The neutral of the inverter generator is bonded to system ground. Connecting loads that also have neutral bonded to ground causes the ground fault detection to trip.

A neutral switch (Generac 6852?) appears to be the safest way to remove the bond to ground in the Lightning Pro Power generator:

The problem I see with that is the same problem for any installation without a neutral switch, the generator in the Sol-Ark 8K wiring diagram bonds neutral and ground at the main panel. As soon as Pro Power senses return current on the ground it will trip the breaker.

There's no code compliant way to get around this. The non-code compliant way to do it is to pull the ground from the power inlet box. I wouldn't do this because I don't understand all of the risks associated with it. I've seen terms like "bolted hot ground fault" and decided it's not worth it.

I have a working system with both a critical loads panel and automatic transfer switch:

But to avoid messing things up and to take advantage of the Sol Ark’s ability to recharge my AGM batteries (260ah) it would seem my only option is installing a neutral switch in the circuit between the truck’s 240v outlet and the connection to the Sol Ark generator port?

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