SolarPowered
Hi. I have a few installation questions. I am an off-grid solar installer down in Mexico. A client was supposed to purchase a generator that was 2 wire start compatible for their off-grid installation but brought down a Generac 11kw HSB G0070321. Their solar equipment is an Outback Flexpower2 system with dual VFX inverters creating 240v across the two hot legs.

I have studied the manual, generator and read most of this forum regarding installation.

There are only 2 spare wires running from the solar system to the generator (in addition to the 4 generator output wires, L1, L2, N, G). Running additional wires may be out of the question. I do not need the Generac ATS, nor any load shedding.

I can run Hot1 and Hot2 from the inverters out to the generator N1 and N2 sense terminals using these 2 wires and then use the Outback aux function and one or two relays to cut the power to N1 and/or N2 when we need the generator to start/run.

Can I cut power to only one of N1 or N2 and have the generator auto start? Is it preferable to cut power to one or the other of N1 and N2? By cutting only one, I am then free to power T1 from the other leg, which at first would be inverter power, and subsequently will be generator power once the ATS units in the inverters switch over to passing generator power to the home.

If the plan of cutting power to only one of N1 and N2 is not possible, then I may install a small ATS inside the generator to initially power T1 from N1 or N2, then jump to generator output.

Luckily I already have 2 premium relays that I could use that have both NO and NC terminals but would prefer to only use 1 if possible. I can imagine that there may be another completely different solution to this problem but getting parts down here is generally a lengthy process.

Should this plan work? And lastly, for this particular installation are any of the 0, 194 and 23 connections necessary for anything? It doesnt seem like it.

Great forum, Thanks,
Casey
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78buckshot
Welcome to the forum, I have zero experience with solar. The only thing I can answer is the question about the N1 and N2 sensing wires, you can cut power to one or both and the unit will start in the 'Auto' mode but it is my understanding that you can't have it set up for two wire start if you choose to use voltage sensing for starting.
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Birken Vogt
You can convert the controller to work on 2 wire start which would be the preferable way to do it.  But that would need another wire, preferably another conduit.  If I may be blunt, if you can't run the proper wires then find a better client.  Also be advised the 11 kw if it is the same old 530 engine will probably leak some oil from the engine, and it needs valve adjustments every 400 hours if not more often.
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Cobranut
I don't see why his plan wouldn't work correctly, but I agree, if the wires can be added I'd do so and run it in 2-wire start mode.
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JayH

That generator really isn't designed for off-grid use, but for intermittent emergency standby. You'll also need a means to keep its battery charged, which could be a small panel and 12-volt charge controller. I'd look into a generator designed for the purpose. You could run the additional necessary wires and configure it for 2-wire start, but I'd look for a genset designed for the purpose.

 

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SolarPowered
Thanks for the responses. I did not choose the generator and will pass on the maintenance tips. The homeowner owns a power-plant in California and wanted to over-do everything solar and electrical, so I don't know how we ended up with such a poorly regarded generator. In the 10-15+kw range I don't really have any reccomendation experience. Of about 100 solar installs I've done here, only 4 have AGS. Everybody else does it manually with modest generators like Honda 2000's, 3000's, and such. Gringo guys here love to check how the batteries and solar are doing 8+ times a day. And once I'm done installing an adequate solar system or upgrade, there's a far greater chance that the generators won't get exercised enough, rather than being run too often. It's sunny here 340 days a year give or take.

This newly constructed, upscale (beach) house is 100% solar-energy efficient (LED lighting, inverter fridge, several small inverter mini-splits across 4 or so self-contained zones, inverter washer, gas appliances), well insulated, double paned (rare here) completely over solar-paneled (8000+w), over batteried, and only intermittently occupied. The only time the generator will come into play is if the occupants arrive during hot months, occupy all 3 bedrooms, and turn on all the AC units at once. Once the house fully cools down the inverter mini-splits will step down to intermittent duty cycles at lower wattages and the solar and batteries can take over and handle it unless it's both hot and quite cloudy. Without AC use the solar system could handle a week+ of darkish cloudy days, which is a years worth of clouds here. If I had to guess we're talking about 60 hours of generator use per year. 100 tops.

I'm going to take a whack at my solution, forgoing 2-wire start. I have all the necessary parts here and ready. The cables I have to use are #12 thhn so running sense power and T1 back there through those wires (45 feet of cable) isn't questionable, and even with 2-wire start I would have to use a relay in the mix. The front yard was just landscaped 2 weeks ago, and the conduit from solar to generator is too convoluted to pull new cable. Wires were pulled one section at a time by the builder, in my absence.

Thanks for feedback,
Casey
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Birken Vogt
External 12 volt does not really work that well, from experience.  It will eat a lot of batteries.  I work in the off grid sector a lot.

Using both sense wires and breaking one of them to cause a start and using the other for T1 should work fine.  It was done a lot on the old first gen units which were harder to convert to 2 wire (more obscure instructions).  I just avoid it because I know better.  It leads to a strange kludgy solution.
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SolarPowered
It's not preferable. This kludgy workaround is brilliant and elegant compared to most of the grandfathered wiring we have here in beach houses, or heck, the local houses off in town on-grid. Still no code or inspections yet. I tend to work as if they are coming-soon.

This is a 48v system. The only thing 12v anywhere near this house is the starting battery on the generator. If the generator tends to be run too often I will reccomend replacing it before it's time comes and goes. And add an external solar charger for the genset battery.

Cheers
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Brian Baughman
The generator can be re-programmed for two-wire start and will require the installation of a two-wire start kit.  The kit contains 2 additional leads that have to be added to the wiring harnesses that plug into the controller.  With two-wire start, the generator only needs the T1 control conductor to keep the battery changer and controller energized, and the two-start circuit.  Please note that using a non-EcoGen generator in an off-grid application will void all Generac warranties on the generator.
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Goofy4TheWorld
Unless the inverter system has the ability to activate two-wire starts for the purpose of exercising the generator, SolarPowered's solution of breaking one sense wire would be necessary to allow the Generac controller to be in charge of the exercising cycle.

But maybe these inverter systems can do that as well???
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SolarPowered
Yes, once I have the ability to start and stop the generator through the inverter system it has the ability to exercise the generator at any schedule of my choosing for as long as I want and done so on any day of the week chosen. How often is recommended for for a Generac 11k given the battery is already being maintained. I'm thinking 15 minutes every 2 weeks, on Sunday mornings at 9am which will augment the morning solar recharge after the most likely evening of the week that the homeowner will have entertained and used more battery capacity than normal. There goes 6.5 hours per year of runtime already.
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78buckshot
Beach environment might be a big issue for the brushed generators due to increased oxidation on the slip rings, I'm just thinking out-loud 'cuz I don't have experience with salty air and beaches. As I write this from our get-a-way place I am thinking about fishing through the ice, probably not the same picture as a Mexico beach. Now, our roadways are a different story. 
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Brian Baughman
Generac air-cooled generators will still exercise on their own when reprogrammed for 2 wire start
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