Hello Everybody,
I started my next phase of solar expansion for my home. So, I have several questions concerning the The Fusion Box with the AC300 system; mostly focused on the charging via AC and PV solar. I need to figure out if I will combine my two AC300’s with the fusion box or just leave them separate systems. I will provide a quick expectation on what I am doing.
I will not need to utilize the 240 VAC output on the Fusion Box.
Whether I use the fusion box or not, I plan on using two small OFF-GRID subpanels using the NEMA TT-30 outputs of the Fusion Box OR from each AC300’s TT-30 outputs.
I am not tying into the grid in the conventional sense but will use two AC in’s to charge during periods of low Solar charging/battery if separate (no Fusion Box). Or use the 30A AC Charging Cable For Split-Phase cable if I go the Fusion Box route.
Here are my questions when using the Fusion Box with the AC300’s. To make my point assume 3 x B300 connected on AC300a and 2 x B300 on AC300b.
Can I connect up to 1200W PV inputs in each leg of both AC300’s (2AC300’s = 4800 Watts total)?
If AC300a (3 batteries) is at 10% charge and AC300b (2 batteries) is at 80% charge, will the PV inputs charge up the AC300a batteries BEFORE it starts charging up the AC300b which is at 80%? E.g. will all 4800 watts of PV charge up ONLY the 3 batteries to 80% to match the AC300b 80% batteries; then charge all 5 batteries up equally from 80% to 100%?
Same question, but with the 30A AC charging cable, not PV.
(The reason I ask this question, I would expect the 2 x AC300’s to properly distribute the PV charge giving 100% priority to the lowest charged batteries. Therefore, if they did NOT give priority to the lowest charged batteries as in the above case, the PV array will quickly charge up the 2 batteries on the AC300b system to 100%, while the other 3 batteries on the AC300a system will only be around 20% with only 2400W charging them while the other 2400W from the AC300b system will be “wasted”).
Another question to incorporate in the above questions. If I only have 2400W of panels (2 arrays of 1200W) If I plug both array legs into PV1 & PV2 in ONE AC300 (say AC300a), then will the other AC300 (Ac300b) without any PV connected to it, then will it still charge the batteries via the PV that is plugged into AC300a?
To summarize, I am trying to figure out if the Fusion box connected 2xAC300’s will be able to smartly distribute the PV to charge the batteries by bringing up the lowest charged batteries first whether the batteries are connected to AC300a or AC300b. OR are the Batteries connected to the two AC300’s still treated as separate systems.
Thank you for anyone (@Derceto@Raymondjram ) that can answer these questions. It will determine how I will wire and setup everything.
Will
I am using the P030A Fusion Box with two AC300 since September 2022 because my large appliances and A/C need 240 VAC. You also need the special 10-pin Communications Cable between the two AC300 units because the output must be in opposite phase and synchonized.
One AC300 is set to Master and it controls the phase of the Slave AC300. Both are set to 30 A charging input from the grid when needed. Each has two set of 800 W PV panels for up to 1.6 kW of solar power per input but the AC300 can only handle 1.2 kW per PV input. This is 2.4 kW per AC300 and 4.8 kW total per hour.
Yes, you can because I have this setup.
No. Each AC300 charges individually. Under the same Sun, both AC300s will charge at the same rate. You can guess which will reach 100% first.
Same as with the PV input. The AC charge rate at 30 A is 3.6 kW per hour for both AC300 equally. Power is never “wasted” because it is not consumed to become wasted. The PV panels are energy pumps, so as soon as the charge reaches 100%, current will not flow at all. This is controlled by the MPPT circuit in each AC300. The AC grid current will also stop at 100%.
The Fusion Box is only for combining the two AC outputs. It has no impact for the charge input.
Thank you @Raymondjram,
That scenario is exactly what I thought, unfortunately.
*Just FYI what I meant by power wasted was “figuratively speaking” -that the PV “power” charging the 100% “A” system could have been applied to the “B” system which would still be low. In the example above, The “AC300a” batteries would be 100% charged say at noon, while the “AC300b” system would not even become fully charged by the end of the day. The power from the AC300a PV array after noon could have been applied to the to AC300b system maybe the words I should have used was Potential Power that could have been created by the AC300a system
For my scenario, I will plan to not use the Fusion box, since I never use the 240w in my home (using gas appliances!). I will just use my 240 to 2x120 splitter to use as the AC lines into each AC300. Plus I can probably setup one AC300 using both PV arrays and the other AC300 using only one PV array and plug the 2nd leg in the DC OUT of the other AC300 (e.g. an extra 200W that would be controllable by the app). I have that setup on one system now and it works great.
So now the fun part, mapping out the power consumption by devices on a daily basis; and that I setup enough power to run day and night and not utilize over 1200 watts in each system at any one time in case passthrough current kicks in during those consecutive cloudy days. MY goal 80% house PV powered 5 months of the year (Central AIR is too much to worry about.) Not enough room for all the extra panels (suburban home and no panels on roof!)
Thank you again for confirming what I unfortunately expected.
Wow, 800 W panels, they must have some weight on them, wish the AC300 could handle 15Amps like the AC500. – MY 550’s were quite heavy…Looking to get 12x410W bifacials super deal delivered @ 0.33/watt.