Growatt SPF 3000TL Question..

Hi folks, I was looking at this package for a home (on grid) power backup. (https://bigbattery.com/products/48v-off-grid-system/). I assume folks have installed and use the Growatt 3000TL Inverter. Does this Inverter work like a UPS in that it switches to battery when it detects and issue with the GRID Connection? I assumed that to connect to Grid (to use to charge when active) I would have to have a generator cut-off breaker/switch in my Breaker box as a safety precaution. Am I thinking correctly? Also.. With the AC out...is that how the Breaker Box is back-fed? And the AC IN is used to power the inverter and charge the battery? I will get an electrician to wire this into the Panel but I want to make sure I have the basic idea of what is going on with this Inverter.

Thanks for any thoughts..
R

Yeah these types of inverters have AC-in, and AC-out on them, they act like an ATS (Auto Transfer Switch), as built-in functionality. A lot of these have generator AC-input on them as well.

There are different policies you can modify in the settings to change the behaviors based on what type of power you want to favor.

They can charge batteries from solar or grid power, if grid goes away, then charging can still come from solar, and inverter circuit runs off the battery.

I would recommend to find the manual on it and get familiar with it to understand about the exact features and adjustability you have.

Some people will wire these into a 'critical loads' panel, if the main panel requires more than one inverter can handle. Then circuits in the house are separated into 2 classes of power, being like 'luxury loads', and 'critical loads'.

In the Growatt manual SPF 3000TL LVM page 17 shows the very 1st program to set up. Program 01 gives you SOL 01 which is solar energy provides the power. The 2nd choice in program 01 is Utl 01 which is Utily 1st. The 3rd choice is SbU which gives you Solar 1st and if not enough solar available will use battery power. This is a very short example the choices have more options attached to each one. I personally use SbU.

Hope this helps

So if the power goes out..and the Battery kicks in, does the risk of putting power back out on the Grid happen... I assume if I don't throw the MAIN that power can move out of the system?

rjpear said:

So if the power goes out..and the Battery kicks in, does the risk of putting power back out on the Grid happen... I assume if I don't throw the MAIN that power can move out of the system?

Click to expand...

The output of this type inverter should never be connected to the grid or the grid wiring. The AC connection for grid charging and pass through, yet that is connected, but this is an Input to the inverter. The output of the invert, not grid connected.

One way to connect these properly is to use a sub-panel. The inverter input from the main panel, the inverter output to the sub-panel. The inverter then does a pass through until the power it out and then turns on its inverter output to continue to supply the sub-panel. Note the inverter must be powered up and on for it to do its job. It will have a constant "idle" load on the battery and can also be charging the battery at the same time. I was a bit puzzled by this at first but that is just the way it works.

Note, not UL approved, as I recall.

I think the Sub Panel would be the way to go. Thanks for the information.