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Growatt 12k passthrough

Oldsawman

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Mar 24, 2022
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Assuming the inverter is wired to the gridSo no neutral is required on the input side of inverter just a ground bonded to the neutral on the main panel and only there am I correct so far? Ok this inverter has a pass thru mode um where is the neutral coming from on the output if the inverter is not inverting but rather just passing thru .the inverter has another ground terminal on it I assume it is to case ground the battery enclosure? Ok so the subpanel has isolated neutral to ground where does the ground for the subpanel come from? They say some people know enough just to be dangerous but danger is id like to avoid when I hook this thing up. Any replies would be appreciated as the manual is no help and actually confusing
 
Generally Earth Ground is supplied by a driven copper clad, steel rod. (or a UFER ground to the footing rebar) A copper ground wire is attached to the ground rod by a clamp or an exothermic chemical welding process, it may have either green (green/yellow) insulation or can be bare copper. The other end of the ground wire is attached to the ground bus bar in the main panel. ALL other equipment that has an exposed metalic frame or metalic chassis must have a continuous ground path that runs back to the ground bus in the main panel.
Ground and Neutral are NOT equivalent or interchangeable. That there is a G-N bond in the main panel does not change this concept. Neutral is a current carrying conductor as are L1, L2 and L3, if present. Under normal circumstances ground should never have current unless there is a malfunction then ground creates a short circuit which will trip a breaker or dissipate the charge so no one gets electrocuted. Neutral on the other hand is supposed to be part of the current carrying circuit when the system is operating normally and should not be used as a substitute for a separate ground wire just because it is bonded to ground at the main panel.
 
Assuming the inverter is wired to the gridSo no neutral is required on the input side of inverter just a ground bonded to the neutral on the main panel and only there am I correct so far? Ok this inverter has a pass thru mode um where is the neutral coming from on the output if the inverter is not inverting but rather just passing thru .the inverter has another ground terminal on it I assume it is to case ground the battery enclosure? Ok so the subpanel has isolated neutral to ground where does the ground for the subpanel come from? They say some people know enough just to be dangerous but danger is id like to avoid when I hook this thing up. Any replies would be appreciated as the manual is no help and actually confusing
You have to connect a neutral from the same source as the hot wires, for pass through.
 
Assuming the inverter is wired to the gridSo no neutral is required on the input side of inverter just a ground bonded to the neutral on the main panel and only there am I correct so far?
If you will only run 240V loads under pass thru power, then you would not need a neutral. If you intend to run anything 120V under pass thru, a neutral will be required.

It will take 4 wires for 120V operation under pass thru. 2 hots, 1 neutral, one EGC (equipment grounding conductor). N-G bond under pass thru will be at the main service panel directly after the electric meter.

You will have to have a subpanel after the GW and it will not have N-G bond. This panel will carry the loads you want to run off the inverter or under pass thru. The EGC runs thru the inverter to this subpanel and it's EGC busbar. Inside the subpanel, there needs to be a neutral busbar not bonded to EGC busbar.

Under inverter power, neutral will be switched by the GW transfer switch and N-G bond will be provided by the inverter, which is source.

Ok this inverter has a pass thru mode um where is the neutral coming from on the output if the inverter is not inverting but rather just passing thru .the inverter has another ground terminal on it I assume it is to case ground the battery enclosure?
The terminal is to provide not only ground to the case but also for running the EGC from the inverter to the loads.

Ok so the subpanel has isolated neutral to ground where does the ground for the subpanel come from?

On the EGC whichs runs to all metal components of the system.

They say some people know enough just to be dangerous but danger is id like to avoid when I hook this thing up. Any replies would be appreciated as the manual is no help and actually confusing
If you aren't certain what you're doing, then educate yourself first. It will prevent equipment damage and possible death or injury. There are various diagrams in the archives here, not hard to find.
 
Sure about that?
Yes, quite sure about it. The only way you could possibly not have neutral would be if there won't be any 120V loads on the system. That's unrealistic in North America.

If you are attempting to run balance current on the EGC, this is what is referred to as objectionable current. Not only is this against NEC, it is very dangerous as current is flowing on the EGC and a ground fault may not trip the breaker.

4 wires- 2 hots, 1 neutral, 1 EGC

N-G bond only at main service panel directly after the electrical meter.
 
Generally Earth Ground is supplied by a driven copper clad, steel rod. (or a UFER ground to the footing rebar) A copper ground wire is attached to the ground rod by a clamp or an exothermic chemical welding process, it may have either green (green/yellow) insulation or can be bare copper. The other end of the ground wire is attached to the ground bus bar in the main panel. ALL other equipment that has an exposed metalic frame or metalic chassis must have a continuous ground path that runs back to the ground bus in the main panel.
Ground and Neutral are NOT equivalent or interchangeable. That there is a G-N bond in the main panel does not change this concept. Neutral is a current carrying conductor as are L1, L2 and L3, if present. Under normal circumstances ground should never have current unless there is a malfunction then ground creates a short circuit which will trip a breaker or dissipate the charge so no one gets electrocuted. Neutral on the other hand is supposed to be part of the current carrying circuit when the system is operating normally and should not be used as a substitute for a separate ground wire just because it is bonded to ground at the main panel.
Thanks and I understand the neutral ground relationship but it doesn't address my questions
 
If you will only run 240V loads under pass thru power, then you would not need a neutral. If you intend to run anything 120V under pass thru, a neutral will be required.

It will take 4 wires for 120V operation under pass thru. 2 hots, 1 neutral, one EGC (equipment grounding conductor). N-G bond under pass thru will be at the main service panel directly after the electric meter.

You will have to have a subpanel after the GW and it will not have N-G bond. This panel will carry the loads you want to run off the inverter or under pass thru. The EGC runs thru the inverter to this subpanel and it's EGC busbar. Inside the subpanel, there needs to be a neutral busbar not bonded to EGC busbar.

Under inverter power, neutral will be switched by the GW transfer switch and N-G bond will be provided by the inverter, which is source.


The terminal is to provide not only ground to the case but also for running the EGC from the inverter to the loads.



On the EGC whichs runs to all metal components of the system.


If you aren't certain what you're doing, then educate yourself first. It will prevent equipment damage and possible death or injury. There are various diagrams in the archives here, not hard to find.
Not helpful
 
So..........
It appears to be a low frequency inverter.
That's using the internal transformer in both modes?
That's an interesting way to deal with N/G bonding.
I like it.
 
I will say there will be objectionable current on the EGC under inverter mode between the main panel and inverter due to the parallel path from the N-G bond, possibly even under pass thru power.

So..........
It appears to be a low frequency inverter.
That's using the internal transformer in both modes?
No, it just passes thru each phase of hots under pass thru. But it does have a center tapped transformer for 120V inverter power.

If I was installing this, I would install a 3 pole transfer switch in order to break the parallel path for inverter mode.
 
I will say there will be objectionable current on the EGC under inverter mode between the main panel and inverter due to the parallel path from the N-G bond, possibly even under pass thru power.


No, it just passes thru each phase of hots under pass thru. But it does have a center tapped transformer for 120V inverter power.

If I was installing this, I would install a 3 pole transfer switch in order to break the parallel path for inverter mode.
Yes, there's still a possibility of objectionable current.
Because of the grids center tapped transformer.
Both Transformer's are bonded to ground.
It's a complicated situation, trying to mix two split-phase systems.
 
This would be a good way to get split-phase configuration, from a non split-phase source.
In combination with an inverter.
 
In bypass mode, you really need to be using the neutral from the same source as the hots.
That is why I think it would be best with a 3 pole double throw. Cut the hots from main and neutral from main. There won't be any pass thru power unless an automatic 3 pole is installed.

Or wire in a relay for N to switch when under inverter power, if there is a relay control built into the GW 12K.

This is a case of purchasing a unit without a clear plan on how to wire it and understanding how parallel paths create objectionable current on the EGC.
 
It does appear to have a NO/NC relay control on the unit. This could be wired to an automatic TA that is 3 pole or a relay to switch N. 1648223380118.png
 
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