GVSolar
Solar Enthusiast
- Joined
- Jan 6, 2020
- Messages
- 455
My system: Schneider Conext SW4024, 3kw DC coupled panels, 3kw Enphase AC coupled panels, 2 Conext MPPT 150/60 SCCs, Combox and SCP. Approx. 25kwh of batteries (20kwh of Gyll, EG4, Lifepower4 and 5kwh of refurbished BYD/TechDirect). Off-grid for 30+ years. Original SW4024 online since 2013.
Using a backup philosophy of 1 is none and 2 is 1, I’ve purchased an additional SW4024 as an emergency backup to my AC/DC coupled SW4024 setup.
Here’s the scenario: I’d like to add the backup SW4024 (to the AC input of my original inverter) in order to increase the output capacity of the system. Currently, the peak continuous output is 3500w; by adding the new unit I should be able to increase that to as much as 7000w continuous. Both inverters will be connected to the same 25kw battery bank.
However, I am also AC coupled (to 3kw of Enphase M215s). This additional AC input is used for mini-splits and car charging when sun is available. It adds as much as 3kw to my daylight AC output capacity – and charges my batteries when not consumed by loads. This has been working flawlessly - although passing clouds can and do scramble my usage. Because the M215s are of an older generation they don’t respond proportionately to frequency shifting – they only stop/start according to the frequency shift.
This AC coupling works well with one inverter, but with two? Since the new SW4024 would connect on AC input (and appear as the grid) the original SW will sync to that input – and theoretically the M215s will sync to that in turn.
New Proposed Setup:
New Backup Inverter: SW/B, Original Inverter: SW/A,
SW/B AC OUT -->AC IN of SW/A -- AC OUT -->MAINS<--- M215s. DC SCCs and both inverters connected to the same battery bank.
Questions:
@400bird @wheisenburg @pvdude @BentleyJ @RCinFLA @JoeHam @Horsefly @GXMnow @Matruco
Many thanks in advance for your replies.
Using a backup philosophy of 1 is none and 2 is 1, I’ve purchased an additional SW4024 as an emergency backup to my AC/DC coupled SW4024 setup.
Here’s the scenario: I’d like to add the backup SW4024 (to the AC input of my original inverter) in order to increase the output capacity of the system. Currently, the peak continuous output is 3500w; by adding the new unit I should be able to increase that to as much as 7000w continuous. Both inverters will be connected to the same 25kw battery bank.
However, I am also AC coupled (to 3kw of Enphase M215s). This additional AC input is used for mini-splits and car charging when sun is available. It adds as much as 3kw to my daylight AC output capacity – and charges my batteries when not consumed by loads. This has been working flawlessly - although passing clouds can and do scramble my usage. Because the M215s are of an older generation they don’t respond proportionately to frequency shifting – they only stop/start according to the frequency shift.
This AC coupling works well with one inverter, but with two? Since the new SW4024 would connect on AC input (and appear as the grid) the original SW will sync to that input – and theoretically the M215s will sync to that in turn.
New Proposed Setup:
New Backup Inverter: SW/B, Original Inverter: SW/A,
SW/B AC OUT -->AC IN of SW/A -- AC OUT -->MAINS<--- M215s. DC SCCs and both inverters connected to the same battery bank.
Questions:
- Will the AC coupling work at all using two inverters? Magic Smoke is not a good option.
- I'm assuming that both A&B should be set to AC couple. True?
- Will the frequency shift from SW/B knock SW/A off-line? Perhaps adjust AC input acceptable parameters?
- How would the new/old units be best programmed? AC Support? Load Shave? Battery Charge/ReCharge? Other settings?
- Any neutral issues to be aware of?
@400bird @wheisenburg @pvdude @BentleyJ @RCinFLA @JoeHam @Horsefly @GXMnow @Matruco
Many thanks in advance for your replies.
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