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where2 · 02-07-16, 11:24 PM

Until Enphase gets around to creating a Power Wall, I'd go with:
"you can put the PV feed ahead of the transfer switch so that it remains connected to the grid. When the transfer switch goes off, the PV system is attached to the grid and not to the generator."

There is no down side to having the PV attached to the grid when the grid is down. I really prefer the simplicity of leaving the PV attached to the grid when the grid is down. I also expect this is how the NEC likes things and expects things to be wired as well.

With a 10kW generator, this isn't like the scenario I've read others contemplating where they want to insert a 300-500W pure sine wave inverter to trick the enphase inverters into waking up to create a micro-grid with a battery charger system that charges the battery used to drive the PSW inverter used to wake up the system, plus the home's base load.

Your 10kW generator setup is literally like taking two generators and attaching them together, or attaching your generator to the grid while the grid is actually live. Something will go, and it will NOT be inexpensive to repair what goes. Keep it simple, keep the PV on the grid side of the automatic transfer switch so it stays with the grid when the generator is running.

In vague theory, the micro inverters adding to the generator AC output should rapidly go outside the stored voltage profile and automatically trip the enphase over-voltage disconnect. Reading through the latest Enphase Envoy setup manual today, there were multiple faults described where one could have to reset a logged fault in the micro inverters which locked them into a solid red light disconnected condition. I'd certainly hate to have to call Enphase and say my entire array is locked up with a red light fault on every micro inverter.

02-07-16, 11:24 PM	#4
where2 DIY Geek Join Date: Apr 2013 Location: Sunny Florida Posts: 401 Thanks: 74 Thanked 83 Times in 73 Posts	Until Enphase gets around to creating a Power Wall, I'd go with: "you can put the PV feed ahead of the transfer switch so that it remains connected to the grid. When the transfer switch goes off, the PV system is attached to the grid and not to the generator." There is no down side to having the PV attached to the grid when the grid is down. I really prefer the simplicity of leaving the PV attached to the grid when the grid is down. I also expect this is how the NEC likes things and expects things to be wired as well. With a 10kW generator, this isn't like the scenario I've read others contemplating where they want to insert a 300-500W pure sine wave inverter to trick the enphase inverters into waking up to create a micro-grid with a battery charger system that charges the battery used to drive the PSW inverter used to wake up the system, plus the home's base load. Your 10kW generator setup is literally like taking two generators and attaching them together, or attaching your generator to the grid while the grid is actually live. Something will go, and it will NOT be inexpensive to repair what goes. Keep it simple, keep the PV on the grid side of the automatic transfer switch so it stays with the grid when the generator is running. In vague theory, the micro inverters adding to the generator AC output should rapidly go outside the stored voltage profile and automatically trip the enphase over-voltage disconnect. Reading through the latest Enphase Envoy setup manual today, there were multiple faults described where one could have to reset a logged fault in the micro inverters which locked them into a solid red light disconnected condition. I'd certainly hate to have to call Enphase and say my entire array is locked up with a red light fault on every micro inverter.