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Growatt SPF 3000TL LVM Inverter & EG4 48V100AH Battery

If the inverter is wired correctly, you shouldn't have an open neutral. (This would indicate a problem)
 
When the inverter is in bypass mode. Grid power is passed through to the loads. In this case the loads panel is a sub panel. It should be grounded, but not locally bonded. Because, a bond already exists in the main panel.
When in inverter mode, the grid is disconnected from the loads. Which makes the loads panel, the main panel. (Which is no longer connected to the previous N/G bond) while some people are ok with a floating neutral, in this situation. If a hot wire shorts to ground, the breaker will not open the circuit.
Ignoring the safety issue, for the moment. If the inverter switches back to bypass mode, while a short exists. The inverter could be damaged. Especially the bypass relays.
The way I understand it is, grounding should only take place in one location. In bypass mode since the main is grounded, I do jot ground my subpanel.
 
The way I understand it is, grounding should only take place in one location. In bypass mode since the main is grounded, I do jot ground my subpanel.
Grounding happens everywhere.
Bonding only happens in one place. (Main Panel)
 
Grounding only at the main panel, I got from Will Prowse.

The jumper to fix open neutral I got from Watts247.

I trust both those sources.
 
When the inverter is in bypass mode. Grid power is passed through to the loads. In this case the loads panel is a sub panel. It should be grounded, but not locally bonded. Because, a bond already exists in the main panel.
When in inverter mode, the grid is disconnected from the loads. Which makes the loads panel, the main panel. (Which is no longer connected to the previous N/G bond) while some people are ok with a floating neutral, in this situation. If a hot wire shorts to ground, the breaker will not open the circuit.
Ignoring the safety issue, for the moment. If the inverter switches back to bypass mode, while a short exists. The inverter could be damaged. Especially the bypass relays.
My understanding now is when the inverter with program setting 1 - SBU and Utility is now power the load. That is Inverter in bypass mode, correct?
Is floating neutral the same as open neutral ? you said: If the inverter switches back to bypass mode, while a short exists (after in iverter mode) . The inverter could be damaged. Especially the bypass relays. So what was the solution u know of?
 
My understanding now is when the inverter with program setting 1 - SBU and Utility is now power the load. That is Inverter in bypass mode, correct?
Yes

Is floating neutral the same as open neutral ?
No
Floating means not bonded to ground

you said: If the inverter switches back to bypass mode, while a short exists (after in iverter mode) . The inverter could be damaged. Especially the bypass relays. So what was the solution u know of?
A N/G bond needs to be made, when in inverter mode. And removed in bypass mode. Because the N/G bond in the main panel takes over.

You need to see if your inverter does this automatically.
 
You'll want to read this (and related threads) on how the Growatt's handle grounding. Specifically slide 19 (at the current revision), regarding mobile versus stationary.
 
You'll want to read this (and related threads) on how the Growatt's handle grounding. Specifically slide 19 (at the current revision), regarding mobile versus stationary.
Thanks Sir for the link. Will read and try to understand as I believe i would. as I had taken Residential Wiring w NE 2002 long time ago .
 
Yes


No
Floating means not bonded to ground


A N/G bond needs to be made, when in inverter mode. And removed in bypass mode. Because the N/G bond in the main panel takes over.

You need to see if your inverter does this automatically.
Thanks for the education.
Seemed like u recommends NO AC input and make the load center a main panel with N/G bonded but will have to add ground rod. I do have a follow-up question:
The Growatt 3K ES Model I bought. The inverter AC input and output terminals are bonded together as I measured their continuity. While in the inverter mode, even no utility/grid current is feeding the load, don't u think, the inverter AC output ground wire is still connect to my Home Main 200 Amps Service panel via the AC input ground wire? I am tapping my AC input from a 70 amps sub panel with N&G separate.
 
All inverter ground input and output terminals are connected to the case. They have continuous continuity.
 
You'll want to read this (and related threads) on how the Growatt's handle grounding. Specifically slide 19 (at the current revision), regarding mobile versus stationary.
A newer model Growatt SPF 3000 TL LVM-24P – model# SKSL00.0010700 is not covered in the above linked pdf.

The following link discusses the newer model.

https://diysolarforum.com/threads/f...-growatt-spf3000tl-lvm-24p.35892/#post-451811

Whenever using AC out there is NO ground on this model. If you have a device that tests for a ground, you will need your own bond on the AC out. I use a bonding plug.
 
I see and that make sense. How do you do the jumper?

Do I connect the AC input to an existing outlet only when the battery is running low or have it connected all the time and the system will take care of itself - switch to grid power when no power from the battery?
Yeah do not do this, it creates an electrical loop, although it is sorta smart and is absolutely a bad idea for various reasons like lightning. On your Growatt go into battery settings and adjust the max discharge voltage so that it stops pulling from battery at whatever volts you want and leave enough room to keep the inverter powered on so you can see whats up with wifi. Lead-acid for example you can only use 50% of the battery, so set min no lower than 46v, if Lifepo4 most cell brands go discharge to 2.5v or 40v in a 16s 48v pack.
With 48v EG4(lithium) like you are considering to pair with this config, it has it has its own BMS and will stop discharge when the battery reaches its safest Min voltage discharge.
 
A newer model Growatt SPF 3000 TL LVM-24P – model# SKSL00.0010700 is not covered in the above linked pdf.

The following link discusses the newer model.

https://diysolarforum.com/threads/f...-growatt-spf3000tl-lvm-24p.35892/#post-451811

Whenever using AC out there is NO ground on this model. If you have a device that tests for a ground, you will need your own bond on the AC out. I use a bonding plug.
Great point on considering the ground. My 2 Stacked SPF 3000TL LVMs have their AC Out via a 2 wire(Black,White,Green) 8awg romex going into a circuit panel and in that circuit panel, as it's the last common junction, I installed two grounding rods right outside and connected those to the circuit box which has 2 breakers each sending 110v into their given rail inside the circuit panel. Neutral is bonded ground in this panel although separate bar and receives the ground wire coming from each growatt.
each Double Breaker in this panel that are connecting to two rails at the same time receive 220v and pull power from both growatts at the same time, which are both connected to the same two battery packs and each carry their own charging source (1 solar panels on Growatt1, and inverter generator into the AC input on Growatt1, which will auto power on when the battery pack reaches Low volt as dected by the dry contact signal switch on the bottom of the growatt see manual page 11) turning on the gen to charge batteries when solar is not enough, hopefully long before the BMS shuts down battery power.
 
... which will auto power on when the battery pack reaches Low volt as dected by the dry contact signal switch on the bottom of the growatt see manual page 11) turning on the gen to charge batteries when solar is not enough, hopefully long before the BMS shuts down battery power.
There is no 'dry contact signal switch' on my GW, nor is there a program 24.
 
And that's why you get the ES?

Does the ES have the dry contact relay only, not the non-ES?
Apparently, my model is the anomaly.

However, It does work out well for my mobile system. In addition, everything worked fine until when the HVAC gas furnace in the house would not run without a ground during a winter power outage. I added an NGB plug into the AC out which corrected the problem.
 
Apparently, my model is the anomaly.

However, It does work out well for my mobile system. In addition, everything worked fine until when the HVAC gas furnace in the house would not run without a ground during a winter power outage. I added an NGB plug into the AC out which corrected the problem.
Or is it possibly a copy? I don't know.
 
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