Inverters in general should not be supplied from RCD protected circuits, as most RCDs and RCBOs are not bi directional, and therefore are not suitable for solar or battery installations. and as for double pole isolation this is the best I can come up with Because most systems use the 1 amp fuse/detection breaker between the array negative and safety ground. it turns a ground referenced system into floating power system--Which does need two pole breakers for safety

old school sparks said:

Because most systems use the 1 amp fuse/detection breaker between the array negative and safety ground. it turns a ground referenced system into floating power system

Point of order: Most PV installations in the UK are floating on the DC side by design and rely on double insulation for protection against fault plus insulation monitoring, with DC fuses where required for overload protection (in case of reverse current). Other countries' practices may vary, particularly when dealing with older installations. There are some which are functionally earthed (C21e tiles come to mind; from distant memory), which depending on the manufacturers instructions (and it does vary for technical reasons) could be earthed via + or -. For safety this will either have a resistor to limit fault current, or an OCPD (fuse/MCB) to interrupt fault current; in the latter case said device must be monitored and raise an earth fault alarm if it operates.

old school sparks said:

Inverters in general should not be supplied from RCD protected circuits

I don't disagree, albeit mainly coming from the angle of leakage currents causing maloperation or blinding of RCDs. But yes if an RCD (or other earth fault leakage device, including MCCBs with LSIG etc) is present upstream compatibility in all regards should be properly checked.

Jam said:

old school sparks said:

Inverters in general should not be supplied from RCD protected circuits

I don't disagree, albeit mainly coming from the angle of leakage currents causing maloperation or blinding of RCDs. But yes if an RCD (or other earth fault leakage device, including MCCBs with LSIG etc) is present upstream compatibility in all regards should be properly checked.

"In general" isn't always the case ... we can't forget TT systems "in general", but also I've seen an inverter arrangement actually supplied  with 30 mA RCDs for the installation.

Jam said:

old school sparks said:

Inverters in general should not be supplied from RCD protected circuits

I don't disagree, albeit mainly coming from the angle of leakage currents causing maloperation or blinding of RCDs. But yes if an RCD (or other earth fault leakage device, including MCCBs with LSIG etc) is present upstream compatibility in all regards should be properly checked.

"In general" isn't always the case ... we can't forget TT systems "in general", but also I've seen an inverter arrangement actually supplied  with 30 mA RCDs for the installation.