Zone-Selective Interlocking Zsi - Siemens 3VA1 100 A Manual

2.6.9

Zone-selective interlocking ZSI

The microprocessor-controlled, zone-selective interlocking function has been developed in
order to control the total breaking time in low-voltage networks with multiple molded case
circuit breakers connected in series.
Regardless of the number of series-connected molded case circuit breakers, all short circuits
in the network can be cleared within a maximum time period of 50 ms.
Note
Downward compatibility
The ZSI function of 3VA molded case circuit breakers is compatible with the ZSI functions of
Siemens 3VL molded case circuit breakers and 3WL air circuit breakers.
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
Description
2.6 Protection system
81