Off grid or passthrough connection

[Buzz]

Newbie with another question: I was reviewing Will's setup for the complete 48v off grid power system and wanted to know how I could add grid power to the mix for battery charging using the same distribution configuration he used? Is that possible or would I have to change the entire setup to a Grid Passthrough Connection? Thanks

 

[Ampster]

I have not seen that video but I am sure it would depend on the type of inverter. Most inverters capable of operating off grid and connecting to the grid have an automatic transfer switch built in. The distribution downstream of the inverter would be the same.

 

[Buzz]

Ampster, I'll have a look at their manual, EG4 6500 inverter, and see if I can find out if it has and auto xfer switch. Thanks

 

[DanielS]

@Buzz Yes it's possible. I'm doing it with no solar with the LV6548's (same as the EG4s) There is AC inputs.

 

[Buzz]

Great! I just wanted to make sure before I started setting things up. I couldn't tell if Will's example had grid input or not just by looking at the video. I don't think it did. I'm not familiar with these type things which is why I asked. You can't be too careful!! Thanks for the help!

 

[Ampster]

@Buzz
The best layout is to use a subpanel fed from the inverter. That can be all the loads or only the ones you want working when the grid is down. The main (grid) panel feeds the inverter and any loads which you don't need when grid is down or would be too many Amps to power in pass through when grid is up. I do not know the specifics of your inverter but that is conceptually how my Outback Skybox works. I run that in Self Consumption Mode but I also sell back to grid when batteries are charged. The only things that are not powered by the protected (critical) loads panel are Oven, electric dryer and EV charger.
The great thing about that layout is that when the Skybox is exporting those loads are offset by solar and only Net is sold to the grid.

 

[ernesto1]

With the EG4 6500 you can wire in utility then setup priority and minimum for utility draw. I have it set at 1st-solar, 2nd-battery, 3rd-utility and 20% battery starts to draw from the grid.

 

[Ampster]

Can the EG4 6500 use external CTs and set limits on export? That may be an alternative to applying for NEM agreement..

 

[Buzz]

@Buzz Yes it's possible. I'm doing it with no solar with the LV6548's (same as the EG4s) There is AC inputs.

Thanks for the comment.... So do you have two of the LV6548s setup like Will wired his EG4s in the video? I guess the only difference is you added the grid AC to your setup right? That's exactly what I want to do! I would start my setup without PV as well. The wiring for me would be the hardest part, I have no experience with electricity but following the video should be fairly straight forward. Thank You!!

 

[Calorim]

@Buzz Yes it's possible. I'm doing it with no solar with the LV6548's (same as the EG4s) There is AC inputs.

@DanielS Quick question regarding your two LV6548s and the AC breaker you used for each inverter. The EG4 lists 60A breaker @120v for AC input on each inverter. The largest single pole breaker I can find for my Square D Homeline is a 50A. That would in theory give me 6k of power for each inverter. What breaker(s) did you use for feeding the grid to each inverter?

This is my first experience with solar. There is a lot to learn and figure out for my first setup.

 

[DanielS]

If you plan to run 240VAC loads then you should be using a 2pole 60A breaker. You would want them to both trip in an overcurrent situation.

 

[DanielS]

Thanks for the comment.... So do you have two of the LV6548s setup like Will wired his EG4s in the video? I guess the only difference is you added the grid AC to your setup right? That's exactly what I want to do! I would start my setup without PV as well. The wiring for me would be the hardest part, I have no experience with electricity but following the video should be fairly straight forward. Thank You!!

Correct, I have 4 Lifepower4’s powering the house for 12 hours of the day and charging at night. I would say this likely isn’t a project for someone with no electrical background though. There is a lot to consider in the design and how you plan to actually tie it into your house.

 

[DanielS]

@DanielS Quick question regarding your two LV6548s and the AC breaker you used for each inverter. The EG4 lists 60A breaker @120v for AC input on each inverter. The largest single pole breaker I can find for my Square D Homeline is a 50A. That would in theory give me 6k of power for each inverter. What breaker(s) did you use for feeding the grid to each inverter?

This is my first experience with solar. There is a lot to learn and figure out for my first setup.

But yes if you wanted to undersized the breaker then you stand the chance of the inverter tripping the breaker if you try to draw too much from the system. I haven’t looked to see if you can limit the AC input and output current. You will need breakers on the input and output.

 

[DanielS]

Can the EG4 6500 use external CTs and set limits on export? That may be an alternative to applying for NEM agreement..

You wouldn’t export from these inverters, they are considered Off-grid inverters.

 

[Ampster]

I'm doing it with no solar with the LV6548's (same as the EG4s) There is AC inputs.

You wouldn’t export from these inverters, they are considered Off-grid inverters.

I assumed those AC ports were bidirectional or intended for grid input. Are you saying they are Off grid inverters that can supplement with grid power passing through only from the grid if needed?

 

[DanielS]

I assumed those AC ports were bidirectional.

No it has both inputs and outputs with an ATS in the middle. Can import power from the grid to charge the batteries and feed loads. Different mode settings are used and schedulable to determine if the grid input is present in the system or not. With no solar, you are basically just passing through grid power and charging the batteries and then you can swap to SBU mode and it will use the batteries until they reach the programmed cutoff voltage and then it will auto swap back to Grid. Depending on the settings it will then recharge the batteries. I have mine programmed to only recharge during off peak hours.

 

[Buzz]

Correct, I have 4 Lifepower4’s powering the house for 12 hours of the day and charging at night. I would say this likely isn’t a project for someone with no electrical background though. There is a lot to consider in the design and how you plan to actually tie it into your house.

Correct, I have 4 Lifepower4’s powering the house for 12 hours of the day and charging at night. I would say this likely isn’t a project for someone with no electrical background though. There is a lot to consider in the design and how you plan to actually tie it into your house.

Your right about lots to think about! I found some drawings that appear to be correct. I'm thinking of having an electrician evaluate my location and plans before starting the assembly and then have them perform the final connections. Sounds simple right LOL.

Changing the subject, I understand you're the wind turbine whisperer. I have a cabin at the foot of Shenandoah River that would be perfect for wind power. The wind blows constantly there. I've got to finish the cabin before even thinking about starting another project.....

Thanks again for the help!!

 

[DanielS]

Your right about lots to think about! I found some drawings that appear to be correct. I'm thinking of having an electrician evaluate my location and plans before starting the assembly and then have them perform the final connections. Sounds simple right LOL.

Changing the subject, I understand you're the wind turbine whisperer. I have a cabin at the foot of Shenandoah River that would be perfect for wind power. The wind blows constantly there. I've got to finish the cabin before even thinking about starting another project.....

Thanks again for the help!!

Sorry, I have no wind experience.

 

[Sconn01]

So I have 2 LV6548's wired parallel, basically the exact same setup as shown with Will Prowse's. I am also wiring it to the grid to pull power when the batteries go down too far. Is there not a way to limit the amount of draw being pulled from the grid so not to trip breakers? I currently have one inverter (doesn't matter which of the two) plugged in to a 20amp breaker/circuit. It shows grid tie on the LCD. As soon as I plug in the second inverter to a separate circuit the circuit trips. I thought I had the inverters set to only pull 10 amps from the grid for charging, which certainly shouldn't cause an issue. I can run a couple separate larger circuits from the main, but I don't want to do it only to find out that wasn't my issue as it won't be easily done. Any thoughts are greatly appreciated! Thanks

 

[Steve Fractals]

With the EG4 6500 you can wire in utility then setup priority and minimum for utility draw. I have it set at 1st-solar, 2nd-battery, 3rd-utility and 20% battery starts to draw from the grid.

So is your main grid connection only to AC-In on your inverter (not on main panel) and this then passes all power to your main distribution panel through the inverter e.g. No grid to main distribution box without it getting it from the inverter AC-Out?

Does that work well so you get power to your main distribution box even if solar and battery are down by the inverter passing it all from AC-In through inverter to AC out and then main distribution panel? Will the inverter still start up ok with only power coming from AC when the Sun has set and your batteries have gone flat?