Siemens Argus 7SR21 Technical Manual page 356

7SR21 & 7SR22 Performance Specification
2.16.3 Operate and Reset Time
Attribute
Starter operate time (³ 2 xIs)
t Operate time
op
Reset time
Repeatability
Overshoot time
Disengaging time
Figure 2-2 shows the operate times for the four IEC IDMTL curves with a time multiplier of 1. Figure 2-3 and
Figure 2-4 show the ANSI operate and reset curves respectively. These operate times apply to non-directional
characteristics. Where directional control is applied then the directional element operate time should be added to
give total maximum operating time.
Unrestricted Page 44 of 68
char = IEC-NI,
IEC-VI,
IEC-EI,
IEC-LTI
char = ANSI-MI,
ANSI-VI,
ANSI-EI
char = DTL
ANSI DECAYING
t
res
Value
20 ms, ± 20 ms
K
= ´
, ± 5 % or ± 30 ms,
t Tm
[ ]
op
a
-
I
1
Is
IEC-NI : K = 0.14, a = 0.02
for char =
IEC-VI : K = 13.5, a = 1.0
IEC-EI : K = 80.0, a = 2.0
IEC-LTI : K = 120.0, a = 1.0
é ù
A
ê ú
= + ´
t B Tm
[ ]
op
ê ú
P
I -
1
ë û
Is
for char = ANSI-MI : A = 0.0515, B = 0.114, P = 0.02
ANSI-VI : A = 19.61, B = 0.491, P = 2.0
ANSI-EI : A = 28.2,
, ± 1 % or ± 20 ms
t
d
R
= ´
t Tm
, ± 5 % or ± 30 ms,
[ ]
res
2
-
1
I
Is
for char = ANSI-MI : R = 4.85
ANSI-VI : R = 21.6
ANSI-EI : R = 29.1
, ± 1 % or ± 20 ms
t
res
± 1 % or ± 20 ms
< 40 ms
< 50 ms
© 2013 Siemens Protection Devices Limited
, ± 5 % or ± 30 ms,
B = 0.1217, P = 2.0