Overcurrents cause considerable increase of contact pressure by mutual inductance.
This prevents :
- contacts repulsion,
- risks of contact soldering ,
- risks of priming.
The characteristics of moving contacts are improved during motor start up and allow to obtain the following overcurrents :
1 contact (Nominal current = 125 A) ; Icw = 1 000 A/22,1 sec.
3 contacts (Nominal current =400 A) ; Icw = 3 200 A/10,5 sec.
Brevet Holec