Appendix
B.1 Selectivity
3VL molded-case circuit breakers
System Manual, 03/2009, 110 0110 - 02 DS 01
343
● No characteristics/trips are listed for fuses. The fuse types have the following operating
classes:
Type Operating class
3NA gL / gG
5SA1 "quick-response"
5SA2 "time-lag"
5SB1/3 "quick-response"
5SB2/4 "time-lag"
5SC1 "quick-response"
5SC2 "time-lag"
5SD4/5 gR
5SD6 "quick-response"
5SE2 gL / gG
● Explanation of the abbreviations:
Abbreviation Explanation
line for line protection
motor for motor protection
starter for starter combinations
insulation circuit breaker Switch disconnectors
I
R
Current value of the overload release
I
sd
Current value of the short-time delayed short-circuit release
t
sd
Delay time of the short-time delayed short-circuit release
I
i
Current value of the instantaneous short-circuit release
I
cn
Rated short-circuit breaking capacity
TM Thermomagnetic trip unit
ETU Electronic trip unit
Settings of the LI and LSI releases of the upstream and downstream protective devices for
calculating the selectivity limits:
I
R
1 x I
r
I
sd
max.
t
sd
³ 100 ms
I
i
max.
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