11kw Generac Guardian 2-Wire Start Behavior - Confusion

Selarom

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Nov 23, 2021
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Hello All,

As stated in the title, I have an 11kw Generac Guardian with the Evolution controller (bought in 2015) and a 200 AMP Automatic Transfer Switch (model: RTSR200A3 ). I now have a SolArk 12k with a small battery bank - 9.6kwh.

I finished doing the connection for the 2-wire remote start. I did not alter anything from the original Generator connection to the ATS. I still have to connect the inverter's GEN cables to the ATS' generator terminals. What I did was a test using the "FORCE GEN" Function to make sure it works fine.

When testing, I noticed that the ATS transferred to it's GEN position. I was made to believe that once the 2-wire function is enabled, the generator would not force the ATS as it would be akin to pressing the "MANUAL" start button on the generator. Is this normal behavior? Have any of you had experience working this integration with the SolArk?

I was hoping it would not transfer the ATS so all the GEN power would flow through the inverter where I can monitor/control how much I can use for charging batteries and power the home simultaneously without overloading the generator...

From the line-diagram below, the connection node where the GEN output is distributed to the inverter and the ATS is done at the ATS' terminals (200 amp rated).
I also realize I can disconnect the "Transfer" cable from the ATS and it should not transfer the ATS to it's GEN position, But I need to test that to be sure. I wouldn't like to mess with the ATS original wiring if I can help it.

1671503209872.png
 
In a conventional set up the ATS is the "brains" of the operation. When it senses a grid outage it sends the start signal to the generator and waits for voltage then transfers the contacts. If you manually start the generator when utility power (load output from the Sol-Ark in this case) is still available then usually the transfer switch does not change state.
There may be dip switches or programming options to prioritize the utility side of the ATS so it doesn't transfer simply because the gen is running?
 
In a conventional set up the ATS is the "brains" of the operation. When it senses a grid outage it sends the start signal to the generator and waits for voltage then transfers the contacts. If you manually start the generator when utility power (load output from the Sol-Ark in this case) is still available then usually the transfer switch does not change state.
There may be dip switches or programming options to prioritize the utility side of the ATS so it doesn't transfer simply because the gen is running?

Thank you for the reply. Originally I thought setting up the Stand-by generator would be similar to what you just described. But for Generac stand-by Generators, the ATS is tied dependent on the signal from the generator’s controller. It is the controller that does the Utility Sensing, starting the generator and making the ATS transfer to the generator and transfer back to the utility terminals. I found how the ATS works following this video:


It is from this video that I figured I can just remove the “transfer” signal cable and the ATS should not transfer. Also thought of wiring that signal wire to a small switch so whenever I need to revert to its original configuration and have the ATS do the transfer, I can just flip the switch
 
Update

Installed a small switch for the Trasnfer signal wire. Tested the Gen Start function from the SolArk and it worked as expected, the ATS did not transfer.

Now if the SolArk for some reason goes out of service. All I need to do is flip de signal switch back ON, disable the remote start in the generator and enable the GRID bypass and the house is setup as it used to before the Solar Install.

DE37B7E7-18D2-412E-9EF1-BD6AB7BA767F.jpeg
 
@Selarom,
I know this is somewhat an old post, but I'm planning a setup similar to yours. Currently I have a Generac 16KW (Evolution 2.0 controller) and a Generac ATS. I'm going to add a Sol-Ark 15K and batteries (no solar, yet), and I want to be able to completely bypass the Sol-Ark in case it fails/needs service and essentially be able to get back to my current setup.

My questions to you are (all assuming there is a grid failure):
When you have enabled the 2-Wire Start mode on your Generac what was the sequence of events then when the Sol-Ark commanded (via the 2 wire start wires) the generator to start? Did the Sol-Ark give the generator some time to start/warm up before applying any load on the generator? and likewise for stopping, run the generator a while after removing the load form the generator?

You said when the Sol-Ark commanded the generator to start that the Generac controller commanded the Generac ATS to switch from grid to generator, is that correct? Have you noticed if there is a grid failure that the Generac controller does not switch the ATS from grid to generator (as it normally would if it were not in 2-Wire Start mode)?

Also, in your original post diagram, when you use the manual transfer switch to bypass the Sol-Ark you would also need to turn off 2-Wire Start mode on the Generator controller, right?

Appreciate any other insights you may have in best way to manually bypass the Sol-Ark.

Thanks!
Curtis
 
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