I have been reading the data sheets for a popular PV inverter
http://www.fronius.com/cps/rde/xbcr...rnational/42_0426_0074_EA_149621_snapshot.pdf
page 34
it says:
"Make sure that the grid neutral conductor is grounded. For IT networks (isolated networks without grounding), this is not the case, and operation of the inverter is not possible."
and also
"The inverter is equipped with a universal current-sensitive RCMU according to DIN VDE 0126-1-1. This monitors residual currents from the solar module up to the inverter grid connection and disconnects the inverter from the grid when an improper residual current is detected."
http://www.fronius.com/cps/rde/xbcr...rnational/42_0426_0074_EA_149621_snapshot.pdf
page 34
it says:
"Make sure that the grid neutral conductor is grounded. For IT networks (isolated networks without grounding), this is not the case, and operation of the inverter is not possible."
and also
"The inverter is equipped with a universal current-sensitive RCMU according to DIN VDE 0126-1-1. This monitors residual currents from the solar module up to the inverter grid connection and disconnects the inverter from the grid when an improper residual current is detected."