Siemens 3VA1 100 A Manual page 383

Connection
Use of the ZSI function is conditional upon the connection of a dedicated EFB300 external
function box to each 3VA2 molded case circuit breaker. The EFB300 allows molded case
circuit breakers to communicate with one another, a capability which is a basic requirement
for the ZSI function.
To permit utilization of the ZSI function, EFB300 external function boxes must be
interconnected as illustrated below:
See also
Zone-selective interlocking ZSI (Page 81)
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
Accessories
4.10 EFB300 external function box
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