GroWatt to MAIN PANEL / Battery Only question

[rjpear]

Hi Folks, I just pulled the trigger on a 48V Power Backup system. This includes a Growatt 3000TL LVM Inverter. What I WANT to happen is that the Inverter is connected to the MAIN POWER (200 amp service) to provide power to charge (or keep charged) a 48V battery. I don't have a need for a UPS Style response to a power outage where it automatically kicks in when I have a power outage. I don't have an issue having a gemerator Interlock and having to throw a few breakers to get access to the battery. I WILL be having an electrician do the connections etc but I wondered how you folks would handle this so I can "advise" the electrician on what others have done or the setup you suggest.
Thanks for any suggestions.

 

[DThames]

I used a sub-panel for my critical loads and put the inverter between the main and the sub-panel.

If you want to back feed your main panel, you need a backfeed breaker and an interlock. Do you plan to feed both legs, you need two such inverters if you do.

 

[rjpear]

Sounds like a Subpanel would be the CLEANEST way to go at this point. Thanks..

 

[Cidpineda]

Hi Folks, I just pulled the trigger on a 48V Power Backup system. This includes a Growatt 3000TL LVM Inverter. What I WANT to happen is that the Inverter is connected to the MAIN POWER (200 amp service) to provide power to charge (or keep charged) a 48V battery. I don't have a need for a UPS Style response to a power outage where it automatically kicks in when I have a power outage. I don't have an issue having a gemerator Interlock and having to throw a few breakers to get access to the battery. I WILL be having an electrician do the connections etc but I wondered how you folks would handle this so I can "advise" the electrician on what others have done or the setup you suggest.
Thanks for any suggestions.

get a manual transfer switch RELIANCE 6 breaker or the 10 breaker

 

[Jimmynik1]

How did this turn out? Looking to feed one side of my panel with my growatt 3k.

 

[rjpear]

Well, I am using a Square D gen Panel and only powering the one side (2 Breakers (2 tandems for 4 circuits). So far it is working but I am haven't tested under a full load since it is the Refrigerator (Random power needs) and a Water Pump. The other 2 are just some LED Overhead lights so it's a light draw. So not sure what happens if the Refrigerator and the Pump kick on... meaning does the Growatt and battery have enough to keep things going. I haven't done the research on what they draw but they are both on 15 amp breakers now.

 

[Jimmynik1]

I didn't see how big your bank was to give an estimate on if/how long it could power the fridge/pump but the growatt can likely surge high enough to start your pump. My predator 3k starts mine no problem and they're both rated at 3k.

 

[schmism]

How did this turn out? Looking to feed one side of my panel with my growatt 3k.

Not recommended to do this as its unlikely your house has no 220v breakers (double pole) and these would not work correctly.

A 120v only "critical loads" sub pannel only powered by the growatt is the correct answer. In addtion if you upgrade to a second growatt and want to parellel them for 220v operation that output can be fed to the critical loads sub panel with 220v breaker with no additional work required.

 

[Jimmynik1]

Not recommended to do this as its unlikely your house has no 220v breakers (double pole) and these would not work correctly.

A 120v only "critical loads" sub pannel only powered by the growatt is the correct answer. In addtion if you upgrade to a second growatt and want to parellel them for 220v operation that output can be fed to the critical loads sub panel with 220v breaker with no additional work required.

Nah it's fine. I've been doing it with a predator 3K for literally 5 years.
Have nothing that's 220, I appreciate the concern though.

 

[OffGridInTheCity]

If I'm understanding your question correctly....
I use a combination ATS + MTS. Grid power is the default. When the inverter comes on, the ATS senses it and automatically switches over to use it. When the batteries go low / inverter shuts-off, the ATS automatically switches back to grid. The MTS let's me choose which circuits are fed by the ATS vs Main Panel - e.g. all you have to do is flip the MTS switches from Gen (power from ATS) to Line (main panel power) or back.


The practical thing I like about this setup - is the house just runs on "Grid" as it always did as long as the inverter is not sending power to the ATS. So I can turn off the solar setup to work on it and the house is not bothered when I do this.

The downside of this is that I have twice daily switch-overs between grid and inverter (e.g. sun charges up battery / inverter goes on, battery runs down at night / inverter goes off). This means I need UPS on sensitive circuits such as computers.

 

[Jimmynik1]

If I'm understanding your question correctly....
I use a combination ATS + MTS. Grid power is the default. When the inverter comes on, the ATS senses it and automatically switches over to use it. When the batteries go low / inverter shuts-off, the ATS automatically switches back to grid. The MTS let's me choose which circuits are fed by the ATS vs Main Panel - e.g. all you have to do is flip the MTS switches from Gen (power from ATS) to Line (main panel power) or back.
View attachment 60321

The practical thing I like about this setup - is the house just runs on "Grid" as it always did as long as the inverter is not sending power to the ATS. So I can turn off the solar setup to work on it and the house is not bothered when I do this.

The downside of this is that I have twice daily switch-overs between grid and inverter (e.g. sun charges up battery / inverter goes on, battery runs down at night / inverter goes off). This means I need UPS on sensitive circuits such as computers.

Very nice setup, yeah I don't need anything ATS like I just have a predatorr
3K that I backfeed through interlock kit with l1430 with both hots merged and having no 220 stuff.
Will likely have the growatt do same thing just have the inverter in place of the generator but will connect and turn on everything manually. Basically my setup when it's done on a little wagon or hand card will just sit there until I need it.