Is this a safe use case for an old inverter / solar panels

[timselectric]

I had thought , and I totally could be wrong, that the purpose of a ground-neutral bond in an inverter was to immediately allow a ground fault (a live wire is loose and accidentally touches the metal case of an appliance ) to complete the circuit back to source via the appliance ground cable that then connects to the neutral via the bond , and trips a breaker to disconnect the power quickly.

Correct this is the sole purpose of the grounding system, which is created by the N/G bond.

Are you saying an inverter with no bond, but with a GFCI at the ac out, offers the same protection in the event of a ground fault as described above. ?

Also correct.
In fact, it is a higher level of protection.

 

[davefromlondon]

Thank you, I'm learning , my High school physics teacher would be smiling.

So to confirm:
-A stand alone, no grid, inverter
-12V battery to inverter
- solar panel system/ controller charges battery
- with a GFCI plugged into the ac out of the inverter
- And a 110v appliance plugged into the GFCI
- no ground neutral bond at all
.... is safe

Am I correct

 

[timselectric]

Thank you, I'm learning , my High school physics teacher would be smiling.

So to confirm:
-A stand alone, no grid, inverter
-12V battery to inverter
- solar panel system/ controller charges battery
- with a GFCI plugged into the ac out of the inverter
- And a 110v appliance plugged into the GFCI
- no ground neutral bond at all
.... is safe

Am I correct

Correct

 

[davefromlondon]

Thanks.
What about ground poles for solar panels for lightening protection ?

 

[timselectric]

Thanks.
What about ground poles for solar panels for lightening protection ?

Are you ground mounting the solar panels on poles?

 

[Glock24]

4500W from 12V... that's 375 amps.

I boubt a Chinese no name inverter achieves that.

 

[davefromlondon]

Are you ground mounting the solar panels on poles?

Solar panel floor mounted, slight angle. when I said pokes I meant a grounding copper pole

 

[SomethingAppropriate]

Man i'd be careful doing electrical work near the washer and dryer

Why? Its grounded!

 

[timselectric]

Solar panel floor mounted, slight angle. when I said pokes I meant a grounding copper pole

Ah,
I would recommend an SPD for each PV circuit, located near where it enters the house. To protect your equipment. The ground connection on the SPD can either be connected to your existing grounding system or a separate ground rod (whichever is easier).

 

[Brucey]

Man i'd be careful doing electrical work near the washer and dryer

Nothing to fear. But these are front loaders no fear of something collapsing into the drum.

 

[davefromlondon]

Ah,
I would recommend an SPD for each PV circuit, located near where it enters the house. To protect your equipment. The ground connection on the SPD can either be connected to your existing grounding system or a separate ground rod (whichever is easier).

THANKS. Can you suggest a good SPD ?

 

[timselectric]

THANKS. Can you suggest a good SPD ?

Anything is better than nothing. But a lot of members are fond of the Midnite SPD's.

 

[davefromlondon]

Thanks

 

[davefromlondon]

Just when I thought I had it figured out I watch this video and at 2min 20 sec I see this image where he bonds the ground from inverter to ground from controller to ground, see red arrow , and bonds both to neutral on battery.
...Then also see on ac side of inverter the breaker switch has the inverter neutral bonded to inverter ground, appliance ground and ground earth pole.

Is this correct ? His videos seem credible. This seems to contradict advice earlier in the thread that no neutral ground bond is needed if I use GFCI on the inverter ac output

What am I missing

 

[timselectric]

Just when I thought I had it figured out I watch this video and at 2min 20 sec I see this image where he bonds the ground from inverter to ground from controller to ground, see red arrow , and bonds both to neutral on battery.
...Then also see on ac side of inverter the breaker switch has the inverter neutral bonded to inverter ground, appliance ground and ground earth pole.

Is this correct ? His videos seem credible. This seems to contradict advice earlier in the thread that no neutral ground bond is needed if I use GFCI on the inverter ac output

What am I missing

That video is not for your setup.
You have a portable inverter setup.

 

[davefromlondon]

Thanks. Complex.topic, do forgive me..... I can't see any difference. His setup looks the same

No grid involved

Standalone inverter

12v side : Panels , controller and 12v battery on one side

Ac side : 120v appliance on other side

Grounded.

His 2nd part of video is mobile .

Ok, so ......Is it the grounding aspect that is different ?

 

[740GLE]

Thanks. Complex.topic, do forgive me..... I can't see any difference. His setup looks the same

No grid involved

Standalone inverter

12v side : Panels , controller and 12v battery on one side

Ac side : 120v appliance on other side

Grounded.

His 2nd part of video is mobile .

Ok, so ......Is it the grounding aspect that is different ?

umm his is mounted to plywood

 

[timselectric]

Ok, so ......Is it the grounding aspect that is different ?

Correct

 

[Supervstech]

Ok.

First critique of your plan is do not have two seperate banks of batteries.

Have one huge bank of batteries with bussbar and two pair of cables feeding the two sets of terminal lugs feeding the inverter.

The battery bank needs to have 375+ Amps of output for this inverter, so use beefy 2/0 copper cabes to the bussbar from each battery, and 4/0 copper cables from bussbar to each inverter lug.

This looks like a nice inverter, but if you truly need 4500W of output, a 24 or 48V setup is the way to go.

Channeling enough solar into the bank of batteries to replenish loads will be challenging without several charge controllers...

Each charge controller will be limited to the 12V wattage number, so massive amounts of charge controllers will be needed.

A low cost 60A solar MPPT charge controller will only channel 720W at 12V, that same controller will feed 4 times as much wattage at 48V.

So fewer controllers will be needed.
Also, the cables will only need be 1/4 as heavy.

I know, you already have this, so sure it will work.
But consider the goals and plan well.

 

[davefromlondon]

umm his is mounted to plywood

Thanks. I'd be happy to secure my components to some permanent structure / plywood./ part of shed

Would I be correct to conclude that my "portable " system with no bonding, using GFCI , is , from a safety perspective, similar to this mounted/ grounded/ bonded system and that if I chose to mount my system permanently I could copy this grounded bonded system. Ie ,there is a choice here

 

[davefromlondon]

Ok.

First critique of your plan is do not have two seperate banks of batteries.

Have one huge bank of batteries with bussbar and two pair of cables feeding the two sets of terminal lugs feeding the inverter.

The battery bank needs to have 375+ Amps of output for this inverter, so use beefy 2/0 copper cabes to the bussbar from each battery, and 4/0 copper cables from bussbar to each inverter lug.

This looks like a nice inverter, but if you truly need 4500W of output, a 24 or 48V setup is the way to go.

Channeling enough solar into the bank of batteries to replenish loads will be challenging without several charge controllers...

Each charge controller will be limited to the 12V wattage number, so massive amounts of charge controllers will be needed.

A low cost 60A solar MPPT charge controller will only channel 720W at 12V, that same controller will feed 4 times as much wattage at 48V.

So fewer controllers will be needed.
Also, the cables will only need be 1/4 as heavy.

I know, you already have this, so sure it will work.
But consider the goals and plan well.

Ok, I'm learning here. so I need a higher voltage dc input inverter, this old one is 12v max. thanks

 

[timselectric]

Would I be correct to conclude that my "portable " system with no bonding, using GFCI , is , from a safety perspective, similar to this mounted/ grounded/ bonded system and that if I chose to mount my system permanently I could copy this grounded bonded system. Ie ,there is a choice here

With a different stationary inverter, yes.

 

[davefromlondon]

With a different stationary inverter, yes.

Thanks, the difference being it can be mounted on plywood, is that the only difference ?

 

[timselectric]

Thanks, the difference being it can be mounted on plywood, is that the only difference ?

The type of inverter is the difference.

 

[davefromlondon]

Correct this is the sole purpose of the grounding system, which is created by the N/G bond.

Also correct.
In fact, it is a higher level of protection.

How do I interpret the comment that "GFCI with no Ground Neutral bond is a higher level of.protectuon" with this comment from this video 7min 57 sec.
"A ground neutral bond on ac side of inverter is critical , without it GFCI won't work properly"