Hello,

I am wondering whether someone would be able to help clarify the differences between IEC 62477-1:2022 and IEC 62477-2:2018 when it comes to temporary overvoltages at a system voltage of 1000Vac?

From Table 7 of IEC 62477-1:2022, for a system voltage of 1000Vac, the temporary overvoltage is determined at 2.2kVrms, whereas from Table 101 of IEC 62477-2:2018, for a system voltage > 1000Vac, the temporary overvoltage is determined at 3kVrms. I notice that Note 2 of Table 101 of IEC 62477-2:2018 states that a different reference standard has been used, but it would be good to understand why there is the difference. Is it simply a case that because IEC 62477-2 is for higher voltage converters, the insulation etc. should be designed with higher overvoltages in mind, or is it just an ambiguity in the standard?

I am relatively new to this so there may be something I've potentially missed.

Thank you in advance for your help.

Kind regards,

Finn