Zone Selective Interlocking (Zsi) - Siemens SENTRON 3VA1 Manual

Description
2.6 Protection system
2.6.9

Zone selective interlocking (ZSI)

Microprocessor-controlled, zone selective interlocking (ZSI) 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
Backward compatibility
The ZSI function of the 3VA molded case circuit breakers is compatible with the ZSI function
of the Siemens 3WL air circuit breakers.
82
3VA molded case circuit breakers with IEC certificate
Manual, 03/2019, A5E03603177010-03