Separate ground from household panel? How to ground?

[Puzzled2]

Hello, rank beginner here.
I have just purchased a lux power 6,000 XP, a 14.3 KW wall mounted lithium battery, and (8) 545 Watt solar panels. My plan is to add another 8 panels within the next 6 months. I have a few questions. For the time being I plan to keep it completely separate from my household panel because I'm worried about unintentional back feeding to the grid. So I plan to take a number of circuits from my household panel to put into another smaller panel that I will power with solar. My first question is: These circuits are grounded to the household system and panel. Will this interfere with the grounding of the solar system? I imagine that I will be grounding the solar panels as well. How do I do this? With one or more grounding rods?
Another question is that the solar panels have to be situated about 400 ft from my house, do I need to beef up the wires coming from the solar panel to the house to avoid excessive line losses? I have not yet purchased these wires.
Thanks for any advice, and could you possibly phrase your advice as though I'm 12 yrs old?
Puzzled2

 

[OffGridForGood]

Hello, rank beginner here.

Welcome to the DIY Solar Forum - great first step joining the membership so you can post questions and we can help you.
You list Edmonton AB location - you come under the Canadian Electrical Code "CEC" which although similar to the US NEC, these are not identical, and local (provincial, municipal) regs can add (but not remove) requirements. When you read information posted on the forum always keep in mind the international community here, check where the poster is from as you read comments.

I have just purchased a lux power 6,000 XP, a 14.3 KW wall mounted lithium battery, and (8) 545 Watt solar panels. My plan is to add another 8 panels within the next 6 months.

A good start.

I have a few questions. For the time being I plan to keep it completely separate from my household panel because I'm worried about unintentional back feeding to the grid.

If you set up the inverter properly and feed a separate load centre panel, there will be no back feed to grid.

So I plan to take a number of circuits from my household panel to put into another smaller panel that I will power with solar.

This can be done, however you need to consider from the start what will you do during the short daylight of Nov-Dec-Jan.
Either you need a system that allows you to choose Utility or Solar,
or you need a method to charge the batteries from utility during poor solar days.
Best to think this through early in the design.

My first question is: These circuits are grounded to the household system and panel. Will this interfere with the grounding of the solar system? I imagine that I will be grounding the solar panels as well. How do I do this? With one or more grounding rods?

Since this set up is in a home with an existing utility grid panel - you have a ground (earth-ground connection) and this should remain the one and only "ground" . We will get back to this point in a moment. You will ground the solar panels to the existing home ground, you will not be adding more ground rods at the solar panels. The alum frames and metal support racking of the PV system will connect to a ground conductor (wire) which will run with the PV wires back to the house, and the ground wire will connect to the metal cases of the subpanel, and ultimately back to the main earth ground connection. No new grounding rods.

Another question is that the solar panels have to be situated about 400 ft from my house, do I need to beef up the wires coming from the solar panel to the house to avoid excessive line losses? I have not yet purchased these wires.

When you know the voltage, amperage and distance you plug this information into a DC wire size calculator and it tells you the wire Gauge you need.
You will quickly learn that 400 feet runs are best done with highest possible voltage, and lowest possible amperage that your inverter will support.
Key item: Edmonton (like most of Canada) sees Cold temps, and lower temps mean higher voltage from a solar panel. The Solar panel specs will show you a delta for temperatures, so you can figure out the max number of panels in series without going over the max voltage the inverter can accept. This is a Hard limit. Over-voltage will destroy the inverter - ie poof.

Thanks for any advice, and could you possibly phrase your advice as though I'm 12 yrs old?
Puzzled2

My best advice is to spend time reading the posts on the forum concerning new set ups, grounding, PV string series and parallel set ups, VOC (volts open circuit) until you begin to understand the critical parameters.

If you add a Signature block in your settings indicating your equipment list, members will see your list and not ask you over and over what inverter you are using, what battery you have, how many and what wattage PV your system has - saves a lot of back and forth.

 

[Puzzled2]

Welcome to the DIY Solar Forum - great first step joining the membership so you can post questions and we can help you.
You list Edmonton AB location - you come under the Canadian Electrical Code "CEC" which although similar to the US NEC, these are not identical, and local (provincial, municipal) regs can add (but not remove) requirements. When you read information posted on the forum always keep in mind the international community here, check where the poster is from as you read comments.

A good start.

If you set up the inverter properly and feed a separate load centre panel, there will be no back feed to grid.

This can be done, however you need to consider from the start what will you do during the short daylight of Nov-Dec-Jan.
Either you need a system that allows you to choose Utility or Solar,
or you need a method to charge the batteries from utility during poor solar days.
Best to think this through early in the design.

Since this set up is in a home with an existing utility grid panel - you have a ground (earth-ground connection) and this should remain the one and only "ground" . We will get back to this point in a moment. You will ground the solar panels to the existing home ground, you will not be adding more ground rods at the solar panels. The alum frames and metal support racking of the PV system will connect to a ground conductor (wire) which will run with the PV wires back to the house, and the ground wire will connect to the metal cases of the subpanel, and ultimately back to the main earth ground connection. No new grounding rods.

When you know the voltage, amperage and distance you plug this information into a DC wire size calculator and it tells you the wire Gauge you need.
You will quickly learn that 400 feet runs are best done with highest possible voltage, and lowest possible amperage that your inverter will support.
Key item: Edmonton (like most of Canada) sees Cold temps, and lower temps mean higher voltage from a solar panel. The Solar panel specs will show you a delta for temperatures, so you can figure out the max number of panels in series without going over the max voltage the inverter can accept. This is a Hard limit. Over-voltage will destroy the inverter - ie poof.


My best advice is to spend time reading the posts on the forum concerning new set ups, grounding, PV string series and parallel set ups, VOC (volts open circuit) until you begin to understand the critical parameters.

If you add a Signature block in your settings indicating your equipment list, members will see your list and not ask you over and over what inverter you are using, what battery you have, how many and what wattage PV your system has - saves a lot of back and forth.

Wow! Thank you @OffGridForGood!
That's a lot of great advice in plain English, very much appreciated. I'll get my signature block together with all the appropriate info.
"If you set up the inverter properly and feed a separate load centre panel, there will be no back feed to grid."
You're right I need to think that through! I was just thinking in terms of baby steps, but it is better to get it all organised first. If I connect to the grid (without backfeed) do I need a separate auto transfer switch? Or will the inverter handle that? I had read some posts where people had trouble with just a few stray watts backfeeding, I don't want the power co breathing down my neck...

 

[OffGridForGood]

Generally the back-feed issues are about what we call "grid-tied-net-zero" - I didn't want to get this far down the rabbit hole on the very first reply, but now that we are into a few steps, lets discuss zero-export.
Some users will have a inverter that ties into the main house panel and essentially exports only the amount of power they themselves are consuming. Think of this as a limited export set up, where the inverter has a current sensor on the main utility lines and it attempts to provide just the correct amount of power to keep the utility from supplying or recieving current.
The inverters are pretty fast but it is impossible to catch a big load like say a dryer suddenly shutting off. So the inverter 'accidently' exports a small amount of current before catching itself. Modern electrical meters can detect this type of unauthorized export and then the utility pay you a visit to find out what is going on at your home. To avoid this problem some inverters will deliberately draw a small load from the utility all the time, to avoid any unintended export caused by a sudden load dropping out like the dryer example.
Anyway, from your initial post, I expect zero-export is not what you are attempting/interested in, and all this is just interesting information to know, but not really applicable to your plans.