That is a matter of opinion. For Whatever Reason Ul Determined theRe WAS A Need to have a Standard that Special’s Circuit Breakers for PV Applications.

　　What is the difference between ul489 and ul489b?

　　IS It Okay to use the 1000VDC PV MCCB for My Photovoltaic McCB 750VDC Photovoltaic McCB Traction Photovoltaic McCB Application?