Siemens SENTRON 3VA1 - Page 657

List of abbreviations
C.1 List of abbreviations
3VA molded case circuit breakers with IEC certificate
Manual, 03/2019, A5E03603177010-03
655
Sym-
bol/abbreviation
Meaning
t
b
Delay time (delay of blocking time)
t
d
Response time
t
g
Delay time associated with the adjustable response current; trip time associated
with ground-fault current setting value
t
i
"Virtual" trip time of I protection; highest trip time associated with rated tripping
current of instantaneous trip
T
p
Trip time; delay time; time-lag class
t
r
Trip time associated with current setting value of adjustable overload protection
t
sd
Trip time associated with short-time delayed tripping current; delay time of S pro-
tection
t
S
Fuse pre-arcing time
t
ZSI
Delay time of all molded case circuit breakers which detect the short circuit but do
not receive a blocking signal when ZSI is activated.
U Voltage across main contacts of the molded case circuit breaker
U
e
Maximum voltage; rated operational voltage
U
Nn
Nominal system voltage