Siemens Sentron 3VA - Page 474

List of abbreviations
C.1 Table of abbreviations
3VA molded case circuit breakers with UL and IEC certification
472 Manual, 01/2019, L1V30435333-01
Table C- 2 Meaning of symbols and abbreviations
Symbol/
abbreviation
Meaning
Δt Delay time
I
Δn
Residual current; rated residual current; response current
I
1
Inrush current
I "
KG
Initial balanced short-circuit current
I
2
t Let-through energy
I
B
Take-over current
I
b
Pickup value blocking protection
I
cm
Making capacity; rated short-circuit making capacity
I
cn
Rated short-circuit breaking capacity
I
cs
Maximum rated service short-circuit breaking capacity
I
cu
Maximum rated ultimate short-circuit breaking capacity
I
cw
Rated short-time withstand current; rated short-time current
I
d
Prospective current; residual current; response residual current
I
D
Let-through current
I
g
Ground-fault protection; ground-fault release; ground-fault current setting value
I
i
Instantaneous tripping current; instantaneous short-circuit protection; instantaneous
magnetic protection; rated tripping current of instantaneous trip
I
k
Short-circuit current
I
KD
Uninterrupted short-circuit current
I
K MAX
Maximum short-circuit current
I
Kmaxline
Uninterrupted short-circuit current of system
I
n
Rated operational current
I
nG
Rated operational current (generator)
I
P
Rated peak withstand current, impulse short-circuit current
I
r
Thermal protection; setting current; response value; current setting value of adjust-
able overload protection (pickup value overload protection)
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
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