I have 3 XW Pro 6848 interters configured to run 3 phase powder from my Battery backs and it works great. I am now trying to ty in the grid power which is 3 phase delta with the high leg. The first inverter qualifies the grid AC but, the other two legs are always stuck in qualifying AC. I current have the high leg going into the inverter configured as phase2-master. Is this wrong or is the XW pro 6848 inverter not allowed to connect to 3 phase delta power coming from the grid?
Tying in 3 phase Grid power to my XW Pro 6848 Invertes
- Thread starter cwinward
- Start date
Page 15 of the multi unit guide seems to indicate only wye 3 phase systems are supported https://solar.se.com/us/wp-content/uploads/sites/7/2022/09/XW-Pro-Multi-Unit-Guide-990-91373B.pdf
I assumed from the documentation you referenced that the XW pro 6848 only provides 3 phase in a wye configuration but, it doesn't indicate that 3 phase delta from the grid cannot be fed into the inverters one leg per inverter. I was hoping that this is the case so if the batteries run low the inverters would take the grid power and use it to charge the batteries and also generate 3 phase wye power from the grid. I could be wrong though. I just wanted to check the wealth of knowledge contained in this forum.
zanydroid
Solar Wizard
If you look at the instructions you see that the three phase is generated by N-L of 120V stacked with a common neutral. That strongly suggests Wye input only to me
The standard assumption for an AIO’s charging / grid support capability is that the input voltage and frequency must match output (and you need to have confirmation of more flexible powering capabilities before assuming it’s supported).
Transformer or chargeverter? To support these inverters off your delta supply
The standard assumption for an AIO’s charging / grid support capability is that the input voltage and frequency must match output (and you need to have confirmation of more flexible powering capabilities before assuming it’s supported).
Transformer or chargeverter? To support these inverters off your delta supply
You are correct sir. An insight on my part. Thanks for the heads up.
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,682
I have a 3-phase Sunny Island system (120/208Y).
So far I'm only able to feed it from 120V single phase, also backfeed from GT PV. 56A x 120V = 6.7kW limit.
Master passes grid through, typically 125V for L1. Slave 1 and Slave 2 make L2 and L3, 120V each.
diysolarforum.com
Of course I could use a transformer to connect 240V grid, but still limited to feed-through of 56A x 120V.
I have tried transformers off output the slaves, making two isolated 60 degree vectors off L2 of grid. But while Sunny Island is slipping phase to synchronize with L1, voltage presented to input of slaves swings wildly. Thought after it settled they would connect, but never did.
I changed Sunny Island setting to make 138/240Y. I isolated "N" from ground and used transformers to make a neutral for 120/240 high-leg delta like your grid. (Either center tap between L1 & L3, or 2:1 off L2 and inverter's N). I think I got that one connected, but drew high current for a while and disconnected.
No luck so far. I wanted to be able to use the slaves' pass-through relays and get 13.4kW from/to grid but have not been able.
The inverters have 180 degree and 60 degree increments. Wish they also supported 90 degree.
In your case, 3-phase grid and 3-phase inverter, I think you just need 240 delta to 120/208Y isolation transformer.
That's what I would have done if I ended up with Delta service, but do to exorbitant cost I'm sticking with split phase.
Possibly you could get away with floating neutral of your inverters, and creating a neutral reference lined up with it from the grid. Either a "T" of 1:1 and 2:1 auto-transformers, or a zig-zag transformer. But might still have issues.
KISS and clean, just get a 3-phase isolation transformer.
So far I'm only able to feed it from 120V single phase, also backfeed from GT PV. 56A x 120V = 6.7kW limit.
Master passes grid through, typically 125V for L1. Slave 1 and Slave 2 make L2 and L3, 120V each.
3-Phase SMA Sunny Island (15kW) + Sunny TriPower (30kW)
Showing a work-in-progress assembling 3-phase SMA system. 3x SI-5048-US are configured for 3-phase and produce 120/208Y, rated 15 kW continuous. Sunny TriPower 30000TL-US-10 is 480V delta (or 277/480Y), rated 30 kW. TriPower combiner box will be used, but for now just one string being connected...
diysolarforum.com
Of course I could use a transformer to connect 240V grid, but still limited to feed-through of 56A x 120V.
I have tried transformers off output the slaves, making two isolated 60 degree vectors off L2 of grid. But while Sunny Island is slipping phase to synchronize with L1, voltage presented to input of slaves swings wildly. Thought after it settled they would connect, but never did.
I changed Sunny Island setting to make 138/240Y. I isolated "N" from ground and used transformers to make a neutral for 120/240 high-leg delta like your grid. (Either center tap between L1 & L3, or 2:1 off L2 and inverter's N). I think I got that one connected, but drew high current for a while and disconnected.
No luck so far. I wanted to be able to use the slaves' pass-through relays and get 13.4kW from/to grid but have not been able.
The inverters have 180 degree and 60 degree increments. Wish they also supported 90 degree.
In your case, 3-phase grid and 3-phase inverter, I think you just need 240 delta to 120/208Y isolation transformer.
That's what I would have done if I ended up with Delta service, but do to exorbitant cost I'm sticking with split phase.
Possibly you could get away with floating neutral of your inverters, and creating a neutral reference lined up with it from the grid. Either a "T" of 1:1 and 2:1 auto-transformers, or a zig-zag transformer. But might still have issues.
KISS and clean, just get a 3-phase isolation transformer.
zanydroid
Solar Wizard
No problem. Also I believe these XW are LF design with combined inverter/charger so they do need to match input and output unless you add a separate charger.
Thanks for the the suggestions.I have a 3-phase Sunny Island system (120/208Y).
So far I'm only able to feed it from 120V single phase, also backfeed from GT PV. 56A x 120V = 6.7kW limit.
Master passes grid through, typically 125V for L1. Slave 1 and Slave 2 make L2 and L3, 120V each.
3-Phase SMA Sunny Island (15kW) + Sunny TriPower (30kW)
Showing a work-in-progress assembling 3-phase SMA system. 3x SI-5048-US are configured for 3-phase and produce 120/208Y, rated 15 kW continuous. Sunny TriPower 30000TL-US-10 is 480V delta (or 277/480Y), rated 30 kW. TriPower combiner box will be used, but for now just one string being connected...
Of course I could use a transformer to connect 240V grid, but still limited to feed-through of 56A x 120V.
I have tried transformers off output the slaves, making two isolated 60 degree vectors off L2 of grid. But while Sunny Island is slipping phase to synchronize with L1, voltage presented to input of slaves swings wildly. Thought after it settled they would connect, but never did.
I changed Sunny Island setting to make 138/240Y. I isolated "N" from ground and used transformers to make a neutral for 120/240 high-leg delta like your grid. (Either center tap between L1 & L3, or 2:1 off L2 and inverter's N). I think I got that one connected, but drew high current for a while and disconnected.
No luck so far. I wanted to be able to use the slaves' pass-through relays and get 13.4kW from/to grid but have not been able.
The inverters have 180 degree and 60 degree increments. Wish they also supported 90 degree.
In your case, 3-phase grid and 3-phase inverter, I think you just need 240 delta to 120/208Y isolation transformer.
That's what I would have done if I ended up with Delta service, but do to exorbitant cost I'm sticking with split phase.
Possibly you could get away with floating neutral of your inverters, and creating a neutral reference lined up with it from the grid. Either a "T" of 1:1 and 2:1 auto-transformers, or a zig-zag transformer. But might still have issues.
KISS and clean, just get a 3-phase isolation transformer.
Similar threads
