SolarEdge string fusing

[pv_n00b]

Do you mean that Solaredge should have its inverter listed as not requiring fusing of its strings? That their Isolation Moniter Interupter (IMI) device provides the overcurrent protection?

If they can make the case under UL 1741 then I say go for it. Unfortunately both the NFPA and UL have been resistant to considering anything other than an air gap OCPD. That's why electronic switches have not been accepted for OCPD duty in the past. In theory electronic switches can act as fast or faster than air gap OCPD but there is a failure mode that leaves them connected where a fuse or CB would not be.