Growatt SPF 3000TL LVM Inverter & EG4 48V100AH Battery

[SYKSolar]

I have been following this on Youtube and then over here for a year and is ready to start my first project.

I just received my 2x320W Renogy solar panels from Home Depot. Now I am planning to buy the Growatt SpF 3000TL LVM Inverter and EG4 48V 100AH Battery. I plan to (upgrade) add couple more solar panels and possibly another battery if they work out great in the next 6 months.

I believe they above components I planned to buy are compatible.

I know I have to buy a 20 feet 10 AWG extension cables. I believe I also have to buy the following, most likely all from Signature Solar:
1.) 2 Awg battery cables but what is the lug size? Is their 36" 2 Awg lug size fit the battery terminals?
2.) Did the battery or Inverter come with RS465 Communication cable?
3.) What else do I need?
Suggestions, guidance are very much appreciated and any suggestion where I can get some of the parts with good deal?

 

[Cruzian3]

1) it’s their battery and their cable, so yes it’s the right size terminal lugs.
2) I just used an Ethernet cable.
3) you’ll need more panels. I have 6 320w panels and it’s just right. I bought my panels used off Craigslist. Local pickup.

After you connect everything, use an outlet tester on any of your ac output plugs. You’ll most likely get an open neutral, if you have ac input from the wall. You can fix this connecting a short jumper wire from ac input neutral to ac output neutral.

 

[SYKSolar]

BTW, what do you mean by this?
If you have ac input from the wall. You can fix this connecting a short jumper wire from ac input neutral to ac output neutral.
Why do I need an AC input since I have a DC solar panel input?

 

[Cruzian3]

BTW, what do you mean by this?
If you have ac input from the wall. You can fix this connecting a short jumper wire from ac input neutral to ac output neutral.
Why do I need an AC input since I have a DC solar panel input?

AC input is for when or if your battery runs out of power you can set it up to automatically switch to grid power so that your appliances don't shut down.

But if you're not doing that then you can disregard what I said about the open neutral.

 

[SYKSolar]

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?

 

[Cruzian3]

1) to do the jumper, I used a 3" piece of 12awg romex and attached the 2 neutrals together.



2) for the ac input, I cut an old 10 awg extension cord and connected the Growatt to the outlet and just leave it in there. Then I set it to only use the grid for loads when battery hits 20% soc. I don't use the grid to charge the battery.

 

[SYKSolar]

Thanks

 

[craigcabrey]

1) to do the jumper, I used a 3" piece of 12awg romex and attached the 2 neutrals together.

View attachment 92579

2) for the ac input, I cut an old 10 awg extension cord and connected the Growatt to the outlet and just leave it in there. Then I set it to only use the grid for loads when battery hits 20% soc. I don't use the grid to charge the battery.

What's the idle load of the Growatt when you're just using the grid?

 

[Cruzian3]

What's the idle load of the Growatt when you're just using the grid?

It’s like 1.5 amps. But sometimes it’s just a mere 35 watts.

 

[SYKSolar]

I change my mind. Now I want to buy the ES Model that is Growatt SpF 3000TL LVM-ES . I like the unit works without a battery as well. But Signature Solar is not accepting order at this moment. I don't see MPPSolar has a similar 3K model!

 

[Cruzian3]

Fyi, SS is gonna release their own inverter soon

 

[timselectric]

I wish that they would start selling the 16k Deye.
They wouldn't be able to keep them on the shelves.
They could definitely buy enough to have their own name on them.

 

[oregonsun]

I have been following this on Youtube and then over here for a year and is ready to start my first project.

I just received my 2x320W Renogy solar panels from Home Depot. Now I am planning to buy the Growatt SpF 3000TL LVM Inverter and EG4 48V 100AH Battery. I plan to (upgrade) add couple more solar panels and possibly another battery if they work out great in the next 6 months.

I believe they above components I planned to buy are compatible.

I know I have to buy a 20 feet 10 AWG extension cables. I believe I also have to buy the following, most likely all from Signature Solar:
1.) 2 Awg battery cables but what is the lug size? Is their 36" 2 Awg lug size fit the battery terminals?
2.) Did the battery or Inverter come with RS465 Communication cable?
3.) What else do I need?
Suggestions, guidance are very much appreciated and any suggestion where I can get some of the parts with good deal?

My experience in oregon where the sun often isn't cooperating tells me those two panels are only enough to cover the 24/7 idle load of the growatt, but if you want power you can use you're going to want to max out the panels on the ES model, a full 4k of panels, two panels will be useless except as a battery tender for your car battery. I ran two 440w panels here through the winter on the 3000w 24p growatt and it was useless, I basically lived on a generator and wouldn't notice a difference between two panels and no panels.
If you are in a sunny area in good weather than maybe 4 440w panels would be a good starting point for a useable system in the summer.

 

[mtts]

Panels should be from a wholesaler or FBM or craigs. And you need a lot more of them.

and it's an RS485 connection. And it's just a regular ethernet cable.

 

[SYKSolar]

1) to do the jumper, I used a 3" piece of 12awg romex and attached the 2 neutrals together.

View attachment 92579

2) for the ac input, I cut an old 10 awg extension cord and connected the Growatt to the outlet and just leave it in there. Then I set it to only use the grid for loads when battery hits 20% soc. I don't use the grid to charge the battery.

Hi, just follow up with your solar system that you had advised me on fixing open neutral. How was you system going on?

I just received my pre-ordered Growatt 3K ES system and is ready to hook up with the EG4 48V battery I bought from them. I believe u used Grid AC input just in case solar panel and battery run out of juice which I am going to do to mine as well. Did u have a load center for your AC output? If so, do you ground your load center since utility the AC input is grounded? Thanks

 

[Cruzian3]

Hi, just follow up with your solar system that you had advised me on fixing open neutral. How was you system going on?

I just received my pre-ordered Growatt 3K ES system and is ready to hook up with the EG4 48V battery I bought from them. I believe u used Grid AC input just in case solar panel and battery run out of juice which I am going to do to mine as well. Did u have a load center for your AC output? If so, do you ground your load center since utility the AC input is grounded? Thanks

I've got a 2 breaker panel hooked up to ac out. It is not grounded nor is it bonded. Treated like a subpanel since I'm connected to main via ac input.

 

[SYKSolar]

I've got a 2 breaker panel hooked up to ac out. It is not grounded nor is it bonded. Treated like a subpanel since I'm connected to main via ac input.

Thanks for the info. That is what I am going to do.

 

[timselectric]

I've got a 2 breaker panel hooked up to ac out. It is not grounded nor is it bonded. Treated like a subpanel since I'm connected to main via ac input.

Not bonded is correct in bypass mode.
But, it should be grounded in bypass mode.
In inverter mode, it doesn't have to be either one.
But, I would recommend both.

 

[SYKSolar]

Not bonded is correct in bypass mode.
But, it should be grounded in bypass mode.
In inverter mode, it doesn't have to be either one.
But, I would recommend both.

Can you elaborate - what do you mean by "bypass", give an example and

"it doesn't have to be either one" you mean no jumper for the neutral AC input and output terminals. How do you solve open neutral in Crusian3's case?

 

[timselectric]

Can you elaborate - what do you mean by "bypass", give an example and

"it doesn't have to be either one" you mean no jumper for the neutral AC input and output terminals. How do you solve open neutral in Crusian3's case?

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.