• Have you tried out dark mode?! Scroll to the bottom of any page to find a sun or moon icon to turn dark mode on or off!

diy solar

diy solar

Replacing Generac ATS with Grid BOSS

GridBOSS manual says (page 21):

GridBOSS should use start/stop relay 1 in the normally open connection. Start/stop relay 1 can be
controlled by both manual control and by battery SOC/voltage logic within the EG4 ® Monitor Center.
The generator can also be configured with warm-up, cool-down, and exercise time.

Can somebody post a screenshot or perhaps tell me the steps, how do I manually control relay 1? I want to test that generator indeed starts using the relay.

Linking official forum post for reference
 
Last edited:
All: I called Signature Solar, and got a reply. Apparently, the button will only work if power grid is off. To test generator remote start, one needs to disable grid power, for example by turning off the main breaker on gridBOSS. Then, the button would work.
 
Last edited:
Part of my solar install project would be replacing Generac Auto Transfer Switch with EG4 Grid BOSS. I have two romex wires coming into ATS labelles "AC" and "DC". I _think_ Generac wiring is described here, but not sure what wire does what exactly. Here's whet they look like inside ATS:


View attachment 255496

Generator is a whole-house propane 16kW Generac with remote auto-start.

Presuming a "typical" installation, what would I need to do to swap the ATS to GridBOSS, without loss of functionality? Specifically, I'm concerned with having generator battery charged, so that it can start when necessary. I understand Grid BOSS has a generator start/stop feature as shown here:

View attachment 255497
Once you are satisfied you've got this working, I would be interested in buying the ATS from you (if it's service entrance rated). Eventually I plan to install a MID in it's place, but have the Solis Inverter, so I'll need to use the Solis-Hub MID once they are shipping.
 
The guide that was posted has the instructions on how to do it. That's where 2-wire start is needed. If you look closely at the gridboss diagram, it shows the 2-wire start lines. Otherwise, the power would have to go out for the generator to start and you wouldn't be able to use it as supplemental power.

I still have my ATS in place but my Sol-Ark controls my generator now. (Generator is grid-tied.) The ATS just gives me a nice little grid isolation when the generator is running.
Hi, is it possible to get a detailed description of how your generac is wired to your inverter? So, the generac ATS is still needed with a 2 wire start up feature? I understand the two wire start up but am confused of how to hook up the load power from grid boss/inverter to generac ATS/generator. Thanks for any guidance
 
I had the generac with ATS installed as whole home backup prior to installing my solar. My plan/hope was that the ATS would satisfy the POCO requirements for a disconnect but it didn't. The ATS is wired in normally, all control circuits, etc are in place as you would for a normal whole home backup. The only difference is, I installed the 2-wire start kit and have that connected to my inverter and the controller set to 2 wire start. The generator still does it's monthly test. When the power drops out, nothing happens though, the Inverter takes care of it. I've not been without power long enough to test it. I need to do that this spring some time.

I emailed generac as well as I kinda wanted it to operate differently and they basically said. A. It wasn't possible and B. I should contact my installer for advanced questions. First, I like the guy that installed mine but he's and old codger and his son's do most of the work. They're not exactly technical. Basically, I wanted the ATS to throw on a power outage to disconnect me from the grid and come back when the grid was operational. Kind of like it did before but without the generator starting. From my understanding, the ATS will flip AFTER the the 2 wire start calls for the generator but I need to test yet.
 
I had the generac with ATS installed as whole home backup prior to installing my solar. My plan/hope was that the ATS would satisfy the POCO requirements for a disconnect but it didn't. The ATS is wired in normally, all control circuits, etc are in place as you would for a normal whole home backup. The only difference is, I installed the 2-wire start kit and have that connected to my inverter and the controller set to 2 wire start. The generator still does it's monthly test. When the power drops out, nothing happens though, the Inverter takes care of it. I've not been without power long enough to test it. I need to do that this spring some time.

I emailed generac as well as I kinda wanted it to operate differently and they basically said. A. It wasn't possible and B. I should contact my installer for advanced questions. First, I like the guy that installed mine but he's and old codger and his son's do most of the work. They're not exactly technical. Basically, I wanted the ATS to throw on a power outage to disconnect me from the grid and come back when the grid was operational. Kind of like it did before but without the generator starting. From my understanding, the ATS will flip AFTER the the 2 wire start calls for the generator but I need to test yet.
Great, so do you have the grid boss? If so, did you run L1 and L2, nuetral and ground from the generac ATS?
 
Nope, I've got a Sol-Ark 15k.

My inverter sits in-between my ATS and my main panel. (The location just happened to be perfect for the way everything was run before I started. ) I basically just pulled the wires back, cut the conduit and pushed the cables back, then ran new cables in the ATS side. The guys that installed the ATS didn't do it correctly either. They left the N - G bond in place so I had 2 bonds. I ended up removing the N - G bond in my primary panel as part of the install so my ATS is now my service disconnect. I've got L1, L2, N, G running from the inverter to the ATS.
 
Nope, I've got a Sol-Ark 15k.

My inverter sits in-between my ATS and my main panel. (The location just happened to be perfect for the way everything was run before I started. ) I basically just pulled the wires back, cut the conduit and pushed the cables back, then ran new cables in the ATS side. The guys that installed the ATS didn't do it correctly either. They left the N - G bond in place so I had 2 bonds. I ended up removing the N - G bond in my primary panel as part of the install so my ATS is now my service disconnect. I've got L1, L2, N, G running from the inverter to the ATS.
Great, thanks for the response! That all makes sense. I am still awaiting a response from EG4 on whether I need a Generac ATS. One person, in another group said yes but others no.
 
I don't think you really need the ATS. I was thankful I had it because it allowed me to disconnect the power to do all the work I needed without having to pay the stupid high fee to have the meter pulled. It's another point of failure at this point but I'm leaving it in.

I think if I had to do it over again, I'd probably look at going the charegverter route with the generator.
 
You have to replace the T1 and N (I Believe, this was off the top of my head) with a live circuit to keep it charged. That's how I've seen it done in a couple other videos.

Basically, you'd pull the ATS out, connect the required circuit to keep juice to the gen that it needs, attach the 2 wire start wires, then you just have the normal generator output wires.
 
You have to replace the T1 and N (I Believe, this was off the top of my head) with a live circuit to keep it charged. That's how I've seen it done in a couple other videos.

Basically, you'd pull the ATS out, connect the required circuit to keep juice to the gen that it needs, attach the 2 wire start wires, then you just have the normal generator output wires.
Okay, to be clear, the 8 wire bundle needs only two for the two wire switch and then larger wire (for me its #2 copper) for the L1/L2, ground and neutral from generator to grid boss. In addition, do you think the "smart port" could power the wire running to t1/neutral for battery charging?
 
I didn't count the wires in the bundle so I can't say for sure.

I'm guessing it could but I don't know that unit. Given the size of wire they use to power the charger (and maybe heater?) the current draw has to be pretty low. You'd probably want to make sure you're using the same size fuse on it just in case.
 
I didn't count the wires in the bundle so I can't say for sure.

I'm guessing it could but I don't know that unit. Given the size of wire they use to power the charger (and maybe heater?) the current draw has to be pretty low. You'd probably want to make sure you're using the same size fuse on it just in case.
Thanks for the input.
 

diy solar

diy solar
Back
Top