1. Technical sheet N°1 Using at frequency 60 Hz All cb’s
Published : January 2016
Version V01
Using at frequency 60 Hz

2. Generalities :
Our MV circuit breakers are designed for a using at frequencies of 50 & 60 Hz.
The scope of IEC is “applicable to a.c. circuit-breakers designed for
indoor or outdoor installation and for operation at frequencies of 50 Hz and 60 Hz
on systems having voltages above V”.
IEC standard does not require specific tests for using at 60 Hz but
some criterias have to be checked.
Nameplate : rated frequency marking only required if rating is not applicable at
both 50 Hz and 60 Hz.
LV auxiliaries must be choose for 60 Hz frequency.
Motors are universal type, they can work at 50 or 60 Hz

3. 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 §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 (IEC §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.
Our circuit breakers are installed since a long time in countries with 60 Hz networks (Canada, Brazil, Taiwan, etc…) without any issue.