78
5 Operation
I
Breaking current in kA
k Weighting
factor
n
Max. permissible number of interruptions
X
During the type tests 10000 mechanical operation cycles
were carried out.
Fig. 57
Max. permissible number of interruptions as a
function of the breaking current.
The chart (Fig. 57) relates to one pole of a triple-pole circuit-breaker. Three times the number of the permissible
single-pole opening operations may thus result in a triple-pole circuit-breaker (e.g. 18 single-pole opening
operations with 50 kA).
Weighting factor k simplifies calculation of the max. permissible number of interruptions at different breaking
currents.