Siemens SENTRON Configuration Manual page 31

A
E
- - -
t
sd
t
ZSI
Figure 3-9
The tripping delays that can be implemented with zone selective interlocking are normally
shorter than those achievable with time selectivity, even though selectivity still remains
operative.
The control wires for the electronic trip units are connected to a separate communication
module that is provided for each circuit breaker.
Selectivity for 3VA molded case circuit breakers
Configuration Manual, 08/2016, A5E03603181010-01
Signal output
Signal input
Control wires
Delay time setting for the short-circuit release
Delay time (defined non-operation time) of all breakers that detect the short-circuit and/or
ground fault current and do not receive a "block" signal when ZSI is activated
Zone selective interlocking
Methods of implementing selectivity using circuit breakers
3.5 Zone selective interlocking
31