All In One Inverter Ground

[Pink7]

So my grid ground cable is connected to my breaker box who  goes to home main ground. I have 2 inverters with acc in/out each with ground ( so 4 ground port in all). Could i just connect all those 4 ground together and to my main ground cable?

 

Pink

[Crossy]

Yup.

 

Are your inverters etc. remote from the house? If so, it might be better to set them up as a TT "island" with a local earth rod and no earth connection back to the house ground.

 

This is how our solar car-port is grounded, local rod and 2-core cables to the house.

[Pink7]

21 minutes ago, Crossy said:

Yup.

 

Are your inverters etc. remote from the house? If so, it might be better to set them up as a TT "island" with a local earth rod and no earth connection back to the house ground.

 

This is how our solar car-port is grounded, local rod and 2-core cables to the house.

My inverters is placed near my main breaker box. I will use a new local earth for my 4 x Surge Protectors.

 

Pink

[Pink7]

31 minutes ago, Crossy said:

Yup.

 

Are your inverters etc. remote from the house? If so, it might be better to set them up as a TT "island" with a local earth rod and no earth connection back to the house ground.

 

This is how our solar car-port is grounded, local rod and 2-core cables to the house.

I remember a active member here on the forum had grid ground hit his MPPsolar inverters.. so i would be positive for a plan who not include grid earth/ground. I have a hope to run my setup more or less offgrid. Can you explain TT "island" with a local earth rod? I need to ground 4 ports from inverters inn/out AC ports, and 4 Surge Protectors. 

 

Pink

[Crossy]

I would avoid mixing grounding systems with the inverters and distribution board in close proximity. The risk of getting your body between two different earthing systems which may not be at the same potential is small but definitely non-zero.

 

If you intend running mostly off-grid then you could go with a local ground rod for the house and inverters and completely isolate from any grid provided "earth" (which is actually the incoming neutral from the grid). Have no links between the incoming neutral and any of your earths.

 

You will need to provide a N-E link from your inverter (check the inverter manual it may provide one for you) to ensure that your RCBOs operate correctly when off-grid.

 

When operating on-grid do not link N and E so your grounds are still not connected to any grid stuff, just have L & N going to your transfer switch (so you have a TT system, perfectly legal in Thailand).

 

You should discuss this with your sparks (whose head will likely explode).

 

 

 

[Pink7]

1 hour ago, Crossy said:

I would avoid mixing grounding systems with the inverters and distribution board in close proximity. The risk of getting your body between two different earthing systems which may not be at the same potential is small but definitely non-zero.

 

If you intend running mostly off-grid then you could go with a local ground rod for the house and inverters and completely isolate from any grid provided "earth" (which is actually the incoming neutral from the grid). Have no links between the incoming neutral and any of your earths.

 

You will need to provide a N-E link from your inverter (check the inverter manual it may provide one for you) to ensure that your RCBOs operate correctly when off-grid.

 

When operating on-grid do not link N and E so your grounds are still not connected to any grid stuff, just have L & N going to your transfer switch (so you have a TT system, perfectly legal in Thailand).

 

You should discuss this with your sparks (whose head will likely explode).

 

 

 

Thanks for the info Crossy, there been lots of issues with Growatt spf5000es with Neutral ground bonding ao i guess i dont dare go that route. ( Most on US version as i understand)

 

Pink

[Crossy]

11 minutes ago, Pink7 said:

Thanks for the info Crossy, there been lots of issues with Growatt spf5000es with Neutral ground bonding ao i guess i dont dare go that route. ( Most on US version as i understand)

 

Yeah, I've been reading that too. Most of it is related to how the NEC specifies the required bonding to be "to code" (the NEC is highly prescriptive).

 

If we just let the inverter do its thing and don't wave extra bonds around it should all work just fine.

 

[Pink7]

12mm x 180 cm ground rod for surge proctor is ok size? There is maybe a 16mm version too.. and length 240cm.

 

Pink

[007 RED]

On 1/18/2023 at 1:13 PM, Pink7 said:

12mm x 180 cm ground rod for surge proctor is ok size? There is maybe a 16mm version too.. and length 240cm.

 

Pink

If I was in your shoes, I'd go for the 16mm x 240cm rod.  The deeper the better.

 

FYI.... A tip which I picked up from somewhere in the electrical forum quite some time ago when I was doing my research/design for my small scale system:-

 

1.    Make sure that the ground where you intend to sink the rod is as wet as possible - I hosed the position two or three times a day for about a week before attempting to sink the rod as the ground was rock hard. 

 

2.    Instead of using a lump hammer to wack the rod into the ground and risk bending the rod or hitting my hand, I used my cordless electric drill.  I put the top of the rod into the chuck and switched the drill into hammer mode (like using a masonry drill).  The rod spins and hammers itself into the ground.  Combined with the wet ground, as indicated above, this method worked a treat with minimal effort.

 

⚠️  Before sinking the rod, make sure that there are no utility pipes/cables buried where you're proposing to sink the rod.

 

Good luck.

[Pink7]

1 hour ago, 007 RED said:

If I was in your shoes, I'd go for the 16mm x 240cm rod.  The deeper the better.

 

FYI.... A tip which I picked up from somewhere in the electrical forum quite some time ago when I was doing my research/design for my small scale system:-

 

1.    Make sure that the ground where you intend to sink the rod is as wet as possible - I hosed the position two or three times a day for about a week before attempting to sink the rod as the ground was rock hard. 

 

2.    Instead of using a lump hammer to wack the rod into the ground and risk bending the rod or hitting my hand, I used my cordless electric drill.  I put the top of the rod into the chuck and switched the drill into hammer mode (like using a masonry drill).  The rod spins and hammers itself into the ground.  Combined with the wet ground, as indicated above, this method worked a treat with minimal effort.

 

⚠️  Before sinking the rod, make sure that there are no utility pipes/cables buried where you're proposing to sink the rod.

 

Good luck.

Thanks 007 RED

 

 

Pink

[Crossy]

If you have an SDS hammer then https://www.lazada.co.th/products/makita-sds-plus-earth-rod-adapter-a-65919-i4181530466-s16443208628.html

 

 

I made one from an old SDS chisel with the end cut off and a hole bored. It worked well, was promptly borrowed, and was never seen again ???? 

[BritManToo]

On 1/16/2023 at 8:18 AM, Crossy said:

You will need to provide a N-E link from your inverter (check the inverter manual it may provide one for you) to ensure that your RCBOs operate correctly when off-grid.

I question if you need an RCBO on the output of a hybrid inverter.

The inverter is itself a RCBO.

[Crossy]

5 minutes ago, BritManToo said:

I question if you need an RCBO on the output of a hybrid inverter.

The inverter is itself a RCBO.

 

The manual for our Sofar grid-tie hybrid says "yes". The manual for your inverter is the best place to start.

 

[BritManToo]

2 minutes ago, Crossy said:

The manual for our Sofar grid-tie hybrid says "yes". The manual for your inverter is the best place to start.

Mine was in Chinese and the English translation didn't make much sense.

But it still turned the electric off (no flash, bang, spark) quicker than the fuses could flip when it got shorted.

(daughter + iron + extension lead = short)

[Crossy]

Yeah, practical experience ^^^ ???? 

 

Adding an RCD/RCBO to the output can certainly do no harm ???? 

[Pink7]

My 2.4m ground bar for the 2 DC Surge Protectors are currently 2.3m under ground and 10 cm over ground. My helper want to hammer it to under soil level. Anyone have any views on this?

 

Pink

 

 

[Crossy]

3 hours ago, Pink7 said:

My 2.4m ground bar for the 2 DC Surge Protectors are currently 2.3m under ground and 10 cm over ground. My helper want to hammer it to under soil level. Anyone have any views on this?

 

Don't.

 

How is the cable attached to the rod?

 

Generally, the connection should remain above ground or be in an earth pit to avoid corrosion reducing the effectiveness of your earth.

[Pink7]

17 minutes ago, Crossy said:

 

Don't.

 

How is the cable attached to the rod?

 

Generally, the connection should remain above ground or be in an earth pit to avoid corrosion reducing the effectiveness of your earth.

I have not connected yet, but there is a bolt with a ring in the top to clamp the wire

 

 

Pink

[Crossy]

Just now, Pink7 said:

I have not connected yet, but there is a bolt with a ring in the top to clamp the wire

 

Definitely keep it above ground if it's going to be bolted.

 

Cinch it all up then coat the whole lot with spray-galvanising or a couple of coats of acrylic paint.