Siemens SENTRON 3WL10 - Page 283

List of abbreviations
C.1 Table of abbreviations
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
Manual, 10/2018, L1V30499596002-01
281
Sym-
bol/abbreviation
Meaning
I
s
Limit current with selectivity; maximum short-circuit current for selectivity limit
I
sc
Prospective current
I
sd
Short-time delayed tripping current; response current of S protection; short-time
delayed short-circuit release; short-time delayed short-circuit protection; delay time
of S protection
I
th
Conventional free-air thermal current
I
U
Rated uninterrupted current
R
A
Contact resistance of exposed conductive part ground
t
1
Time of inrush current
t
2
Ramp up time
t
A
Safety clearance
t
g
Delay time associated with the adjustable response current; trip time associated
with ground-fault current setting value
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
U
Voltage across main contacts of the molded case circuit breaker
U
e
Maximum voltage; rated operational voltage
U
Nn
Nominal system voltage
U
s
Rated control supply voltage