First Time Build Questions

[aonangj]

Thank you to those who have helped me via other threads so far to purchase and start to put together my build. I thought it would help to have a singular thread to share the build and ask questions. My many thanks to @Zwy and @OffGridInTheCity (and unknowingly @rodneyhunt) for your contributions already.

Build Details:
7.5kWh Ground Mounted Array

• 14 Adani Solar 530W Bi-facial panels
• Ground Mount Tilt Array based off of @rodneyhunt's plans on youtube

20Kw Split Phase Victron system

• Based off of Current Connected 20kVa Kit
• 2x Victron 48V Quattro 10kVA 120V Inverter 140A Charger (UL)
• Victron Lynx Power In - Power Distribution System (M10)
• Victron Lynx Shunt VE.Can - Power Distribution System (M10)
• Victron Lynx Distributor - Power Distribution System (M10)
• Victron Cerbo GX (MK2) Kit; 5" Touch Screen for system control
• 2x Victron MPPT 250V/100A VE.Can SmartSolar Charge Controller
• EG4 LL-S Lithium Batteries Kit | 30.72kWh | 6 Server Rack Batteries With Pre-Assembled Enclosed Rack | With Door & Wheels | Busbar Covers

Electrical/Panel Tie in

• TBD - Need to figure this out.
• The Inverter setup is in a shed approx. 150' from my main panel in the house

Current Questions:

1. Grounding: I know this is a hot topic. I've reviewed this video and thread but it seems unclear to me. I understand everything needs to be earth grounded, but it doesn't seem clear whether it's better to do a secondary ground rod, or just run it back to the main at the house. Assuming I go with running it back to the house, can I just create a grounding bar in the shed and run all equipment grounds to that AND the PV array to that and then run a bare ground line from there buried with my mobile home feeder back to the main panel?

Thanks all, here is some photos of the build

 

[OffGridInTheCity]

Congratulations on you're progress! I'm wondering how long till you double, triple, ... your PV as it looks like you have room. If I had room and the neighbors wouldn't freak out, I'd plan for 60kw PV so I can make it all winter with no grid

My roof and ground arrays (and panels) are wired to the single house ground with max distance ~200ft to furthest edge of the ground array. However, this is what passed my inspection rather than proof of intelligent design! I've read numerous times that it's also OK to also have a grounding rod at the array.

If you have inspections or electricians as part of you're build - maybe you can consult with them?

Otherwise, personally, the only conclusion I've come to is that grounding (however you reasonably do it) = good. Let us know what you decide.

 

[aonangj]

I'm wondering how long till you double, triple, ... your PV as it looks like you have room.

Ha! Yeah my wife is pumping the brakes there, originally I was going to do twice the size but my wife doesn't want to look at it. We'll see though, I've tried to make the build to be able to take the additional capacity though would require more MPPTs.

If you have inspections or electricians as part of you're build - maybe you can consult with them?

Thanks, speaking with an electrician is kind of my plan if I can find a knowledgable one in this setup. The array would be about what you're setup is, probably 175' or so from the house grounding rod, so that's kind of what I'm thinking right now.

 

[OffGridInTheCity]

Ha! Yeah my wife is pumping the brakes there, originally I was going to do twice the size but my wife doesn't want to look at it. We'll see though,

My wife also hates the look of solar panels; however, I pored on the charm and attention over the last couple of years and she relented so now I have more panels AND a better marriage

 

[timselectric]

The array would be about what you're setup is, probably 175' or so from the house grounding rod, so that's kind of what I'm thinking right now.

Distance to the house ground rod, doesn't matter.
You are connecting to the house grounding system.

I understand everything needs to be earth grounded, but it doesn't seem clear whether it's better to do a secondary ground rod, or just run it back to the main at the house. Assuming I go with running it back to the house

It doesn't need to be earthed , it needs to be connected/bonded to the existing grounding system (at the house).

can I just create a grounding bar in the shed and run all equipment grounds to that AND the PV array to that and then run a bare ground line from there buried with my mobile home feeder back to the main panel?

Yes, that's how it should be done.
Bare wouldn't be my choice. But it is acceptable by code.
Doesn't your mobile home feeder already have an EGC? Or is the mobile home not powered by the same system?

 

[aonangj]

Distance to the house ground rod, doesn't matter.
You are connecting to the house grounding system.

It doesn't need to be earthed , it needs to be connected/bonded to the existing grounding system (at the house).

Yes, that's how it should be done.
Bare wouldn't be my choice. But it is acceptable by code.
Doesn't your mobile home feeder already have an EGC? Or is the mobile home not powered by the same system?

Oh great point! Yes the mobile home feeder is just the type of wire but yes it will ultimately feed into the same bond/grounding so I suppose that would cover it! That wire is a sheathed aluminum bundle

 

[aonangj]

Okay a couple more questions I'm trying to understand from reading the manual, forum posts and watching people's videos.

A/C input and output questions

A/C Input Question
I presently have a buried 20A line already going to the shed that I would love to use for the rarely needed grid/shore-power, but if I'm understanding correctly, it requires 11A. I'm assuming that is 11A per unit, so this means my 20A circuit will not be sufficient, correct? If so I'm going to have to run another 165' cable back to the shed just to have this shore power

Could I just run a second 120v 20a line, or do I need to run a full new 240V (50A?) circuit? From what I'm understanding this would be required if there wasn't enough power from my Battery bank/PV to power the loads correct? Is 50A sufficient in that case?




A/C Output Question
I'm planning to run a full 200A line to the house so that I could theoretically power all loads if I wanted. Given that, trying to confirm the input breaker size coming from the Inverters. Since I will pull a theoretical 200A, I need to have a 200A input breaker with 2/0-2/0-6AWG wire running from each Quattro into the single 200A breaker in the sub panel correct?

The Inverter powered subpanel would look like:

1x 200A input breaker (power in from inverters 1&2)
1x 200A output breaker (power out from shed subpanel to house subpanel)
(Optional) 1x 20A breaker (to a local circuit in the shed for powering the light and a few outlets)

Does this all sound right?

For the A/C input if I don't have to run a new line, I would just split the 20A line from a junction box and run to the two inverters. If I do have to run a new line it will depend on whether that's merely a new 20A 120V line that runs directly to one of the two inverters, or whether I need to run a new 50A line in which case I'd likely have a second subpanel with a breaker just to make it easier.

 

[timselectric]

The output of a Quatro is only 83.33 amps.
Unless you're planning for future expansion, you don't need 200a wire, breakers, or panel.
I'm not sure about the Quatro, but most inverters when stacked together (for a single system) can't have an input to only one unit.
If you want to use the existing 120v grid circuit. You could just plug a battery charger into it.

 

[aonangj]

Just realized to do 200A I think I'm going to have to put a full sized panel in the shed as the smaller ones seem to max out at 125A

 

[aonangj]

You could just plug a battery charger into it.

So basically setup a chargeverter off of the 20A line and don't have any a/c going to either inverter?

 

[timselectric]

So basically setup a chargeverter off of the 20A line and don't have any a/c going to either inverter?

Yes, or a smaller, less expensive charger.
A chargeverter would be a waste on that small circuit.