IEC62271中需要在60HZ单独实验的部分如下：

Rated short-circuit making current (IEC 62271-100 §4.103)
“For a rated frequency of 60 Hz and the standard value of the time constant of 45 ms it is equal to 2,6 times the r.m.s. value of the a.c. component of its rated short-circuit breaking current”.
Temperature-rise (IEC 62271-1 §6.5.2)
“Tests performed at 50 Hz on switching devices of the open type should be deemed to prove the performance of the switching device when rated at 60 Hz, provided that the temperature-rise values recorded during the tests at 50 Hz do not exceed 95 % of the maximum permissible values”.
Power-frequency withstand voltage (IEC60060-1 §17.1)
The test duration is independent of the frequency in the range from 45 to 60 Hz. If not specified by the relevant technical Committee the duration of a withstand test shall be 60 s.
Our tests carried out with a frequency of 50 Hz meet to the requirements above and therefore prove the working at 60 Hz.