BillK-AZ
Senior Member
- Location
- Mesa Arizona
Something does not sound right about this.
Typically we have a main breaker | service entrance bus | inverter breaker | inverter.
Because your main breaker is required to have GFP, the 705.12(D)(3) Exception of this thread requires the inverter breaker to also have GFP.
You seem to have added an inverter GFP device so that you have:
Main breaker (with GFP) | service entrance bus | inverter breaker | GFP device | inverter
The main breaker and the inverter breaker are both required to be suitable for backfeed and also subject to possibly carrying ground fault currents.
A fault in the inverter could possibly cause the inverter to draw current from the grid and also cause ground fault currents.
The inverter breaker has two functions:
As I posted earlier, the manufacturer states that "GFP's can not be backfed in a PV/Solar application".
I do not understand how you can state " but the GFP is not backfed".
Typically we have a main breaker | service entrance bus | inverter breaker | inverter.
Because your main breaker is required to have GFP, the 705.12(D)(3) Exception of this thread requires the inverter breaker to also have GFP.
You seem to have added an inverter GFP device so that you have:
Main breaker (with GFP) | service entrance bus | inverter breaker | GFP device | inverter
The main breaker and the inverter breaker are both required to be suitable for backfeed and also subject to possibly carrying ground fault currents.
A fault in the inverter could possibly cause the inverter to draw current from the grid and also cause ground fault currents.
The inverter breaker has two functions:
- It protects the main bus from excess inverter current (not likely in the real world), and
- It protects all of the wiring and devices on the load side of the inverter breaker in case there is a fault.
As I posted earlier, the manufacturer states that "GFP's can not be backfed in a PV/Solar application".
I do not understand how you can state " but the GFP is not backfed".