Grounding Correct? Or Not?

[Zil]

One thing to think about is a Battery Monitor with a shunt.
I don't know the combiner box so it may have this covered. Parallel panels need be fuse in a special way.

 

[LSC]

Fuse to protect the wire. I would fuse 1/0 marine grade wire at 250 amperes.

Thanks, I will change the main fuse to the inverter from the battery to a 250A T fuse. Why so high? Protecting the wire if I remember correctly. Yes?

Every reference I have to awg of earth grounds list minimal 8 gauge.

I would assume that the ACIN, ACOUT and PV wires as well as the ground wires should also be 8 awg?

There must be only one earth ground when connected to the grid. Do not connect the equipment to that rod

Okay, so connect the panels to that rod but not the units grounded to each other inside? They should be grounded to just the ACOUT ground, yes?

 

[LSC]

I don't know the combiner box so it may have this covered. Parallel panels need be fuse in a special way.

The combiner box is fused with 15A breakers and has lightning protection as well.

 

[LSC]

Okay, I hope this is the last attempt at this! Here is what I have based on all the great advise. Thanks to all. If it is good then I will settle on this design.

 

[timselectric]

Every reference I have to awg of earth grounds list minimal 8 gauge. You are dealing with 25 AC amperes. 8awg will be fine, larger will not hurt. When you are plugged into the grid, your earth grounds must go to the main panel earth ground. That you have. When you are disconnected from the grid, all AC current references back to the inverter case. That you have.
At 24 volts you should be fine with 1/0 awg marine grade cable. That will carry 285 DC Amperes. You need better fuses than ANL for main battery fuse, and closer to battery positive. Fuse to protect the wire. I would fuse 1/0 marine grade wire at 250 amperes. Not those 100 amp ANL.
The purpose of grounding the solar panel frames is for lightning protection. That earth rod should not connect to the equipment. I am open to correction of this, just give me a link to relative national electrical code.
Controversial on internet-->There must be only one earth ground when connected to the grid. Do not connect the equipment to that rod.

This may help to clarify a little. Or, it might make it more confusing. lol (sorry, in advance)
Grounding can be very difficult to understand.

 

[timselectric]

More videos, if interested.

https://youtube.com/playlist?list=PLRNS1x1jcKbGI9QSXgIIBTwzWTkIe6z7t

 

[Dynoman]

Here are a few links for fuses & fuse holders:

www.amazon.com/gp/product/B0017SJOH4

www.amazon.com/gp/product/B0753HBG6N

www.donrowe.com/TFB2-250-250A-Class-T-Fuse-Kit-p/tfb2-250.htm

www.donrowe.com/category-s/1845.htm

Here is a link for 10 AWG solar wire. Wire for Solar Panels often have long runs and 10 AWG will have less losses than 12 AWG. This type of wire is needed for outdoor use. Many wire sheathing cannot stand up to the sun and will fall apart.

www.amazon.com/gp/product/B08ML4RP85/

Hope it helps...

 

[onokai]

This may help to clarify a little. Or, it might make it more confusing. lol (sorry, in advance)
Grounding can be very difficult to understand.

I love the comment at the end about #6 grounding wire size being absurd

 

[MichaelK]

Since I was contradicted for what I stated in post #11, here is a reference for that....

Does Ground Wire Have To Be The Same Gauge? [Explained] - Home Arise

Does ground wire have to be the same gauge? Some say it does. But does it really have to be? We’ve discovered the answer for you. Read along to know the answer...

homearise.com

Does ground wire have to be the same gauge?


The answer is yes. The ground wire, hotwire, and neutral wire should be of the same gauge. Because the gauge size is determined by the load current. Neutral wire returns the same load current in hotwires. For that reason, the wire size has to be the same. But for the ground wire, the size can be bigger and smaller sometimes.

 

[timselectric]

Generally on circuits below 30 amps. The ground wire size matches the current carrying conductors. That's just how it works out in the table. But, this doesn't always apply. So, it's best to check the tables for each situation.

 

[Zil]

Don't confuse "ground wire" used meaning dc negative. Very true, negative and positive must be same gauge.
Then there is "ground wire' used meaning the earth ground in an alternating current. The neutral and hot are the same size and the ground in a circuit (think romax) is not always the same gauge. Not always and not necessary as it serves to trip the breaker while transfering momentary voltage to earth. But the general system ground that connects eventually to the earth ground is larger gauge, as noted above in the chart.

 

[LSC]

More videos, if interested.

https://youtube.com/playlist?list=PLRNS1x1jcKbGI9QSXgIIBTwzWTkIe6z7t

Wow, those are intense and even the guys talking don't always agree on what is the correct way to grounding or bonding. See what I mean. Thanks for the link. I am still confused on my ground rod. They showed a pic of a house with an array connected to a ground rod and the path lightning can take. Ouch. So what to do?

 

[LSC]

Here are a few links for fuses & fuse holders:

Here is a link for 10 AWG solar wire

I am using those exact fuses, so thanks for the links.

 

[timselectric]

Wow, those are intense and even the guys talking don't always agree on what is the correct way to grounding or bonding. See what I mean. Thanks for the link. I am still confused on my ground rod. They showed a pic of a house with an array connected to a ground rod and the path lightning can take. Ouch. So what to do?

The aux ground rod is allowed, but not required.
I would recommend against it. For the reason, explained in the video.

 

[LSC]

So my only question now is that

I would recommend against it.

I agree. So do I run the 6 awg wire from the array to the combiner box and then 6 awg from there to the ground lug in the ACin breaker box?

 

[timselectric]

So my only question now is that

I agree. So do I run the 6 awg wire from the array to the combiner box and then 6 awg from there to the ground lug in the ACin breaker box?

#6 from array to combiner box. From the combiner box to main ground bar can be sized by the equipment ground table. (As long as it is in conduit)

 

[LSC]

equipment ground table

Is there a link to this, I didn't see one in any post. If it is in relation to the wires I have running between the components (now 10 awg) then I would use a bare 10 awg wire from the combiner to the busbar in the ACin breaker box?

Latest drawing.

 

[timselectric]

Is there a link to this, I didn't see one in any post. If it is in relation to the wires I have running between the components (now 10 awg) then I would use a bare 10 awg wire from the combiner to the busbar in the ACin breaker box?

Post #22

 

[LSC]

Post #22

Thanks, I think I have it right now with the last pic I put in above. Wow!

 

[Dynoman]

If you have not picked up bus bars yet these are hard to beat.
www.amazon.com/AMRB-2127-Blue-Sea-MaxiBus-250/dp/B07BVDYCCX/ref=sr_1_2

Cover for bus bar is nice to have...
www.amazon.com/Blue-Sea-2719-Maxibus-Cover/dp/B011KK3K1Y/ref=sr_1_2

 

[LSC]

If you have not picked up bus bars yet these are hard to beat.

I have ones just like them w/covers that are 250A. Thanks for the links.

 

[tonyg]

Every reference I have to awg of earth grounds list minimal 8 gauge. You are dealing with 25 AC amperes. 8awg will be fine, larger will not hurt. When you are plugged into the grid, your earth grounds must go to the main panel earth ground. That you have. When you are disconnected from the grid, all AC current references back to the inverter case. That you have.
At 24 volts you should be fine with 1/0 awg marine grade cable. That will carry 285 DC Amperes. You need better fuses than ANL for main battery fuse, and closer to battery positive. Fuse to protect the wire. I would fuse 1/0 marine grade wire at 250 amperes. Not those 100 amp ANL.
The purpose of grounding the solar panel frames is for lightning protection. That earth rod should not connect to the equipment. I am open to correction of this, just give me a link to relative national electrical code.
Controversial on internet-->There must be only one earth ground when connected to the grid. Do not connect the equipment to that rod.

Hello!
Controversy everywhere I look for grounding advice... lots of debate, never reaching a consensus...
for an off-grid setup, is it ok to have it all (equipment + panels and frames) connected to one earth ground rod only?

 

[timselectric]

Yes
The one that your main service panel is connected to.

 

[tonyg]

Yes
The one that your main service panel is connected to.

All ground wires to a bus bar with one bonding with system neutral and then from the bus bar to the earth rod.
Or is it advised to take the panels' ground wire straight to the earth rod?

 

[timselectric]

Option 1