"Variation of tripping thresholds of MCBs according to network
frequency
The circuit-breakers are calibrated for a current with a frequency range between 50 and 60 Hz.
For other frequency values, the electro-magnetic tripping current varies according to the multiplication
factor H.
D.C. 100 Hz 200Hz 400Hz
H 1.5 1.1 1.2 1.5
For the thermal trip, on the other hand, there is no variation because it is independent of the network
frequency.
Example:
S 202 C10 supplied at 50-60 Hz, the electro-magnetic tripping current is: 50 A≤Im≤100 A;
S 202 C10 supplied at 400 Hz, the electro-magnetic tripping current is: 75 A≤Im≤150 A."