Arcing spaces for Molded Case Circuit Breakers 3VA
During planning and installation of the Molded Case Circuit Breakers, sufficient arcing spaces have to be observed.
The following needs to be considered espacially:
- Ventilation holes must be kept free
- Ionised gas must not be directed towards terminals or non-insulated busbars
- Arcing spaces must not be blocked by busbars installed too close or any other items
Molded Case Circuit Breakers 3VA up to 630 A frame size are equipped with a double-rotary contact system, and are thus ventilating into both directions. The upper ventilation holes (terminals 1, 3, 5) are located above the terminals; the lower ventilation holes (terminals 2, 4, 6) are located below the terminals.
Molded Case Circuit Breakers 3VA of the frame size 1000 A, as well as Molded Case Circuit Breakers 3VL have a single contact system and ventilate only in the direction of 1, 3, 5.
Further information concerning necessary isolation measures can be found in this FAQ: