Siemens 7SR18 Solkor, Manual

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7SR18 Performance Specification
Unrestricted ©2018 Siemens Protection Devices Limited Page 27 of
2.7.3 Operate and Reset Time
Attribute Value
Starter operate time (
≥
2 xIs ) 20 ms,
±
20 ms
t
op
Operate time
char = IEC-NI,
IEC-VI,
IEC-EI,
IEC-LTI
[ ] Tm
K
t
Is
I
op
×
−
=
1
α
,
±
5 % or
±
30 ms,
for char = IEC-NI : K = 0.14,
α
= 0.02
IEC-VI : K = 13.5,
α
= 1.0
IEC-EI : K = 80.0,
α
= 2.0
IEC-LTI : K = 120.0,
α
= 1.0
char = ANSI-MI,
ANSI-VI,
ANSI-EI
[ ]
Tm B
A
t
P
Is
I
op
×








+
−
=
1
,
±
5 % or
±
30 ms,
(ANSI-EI +5% -10 % absolute for I/Is>10 with TMS >2)
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,
B = 0.1217, P = 2.0
char = DTL
t
d
,
±
1 % or
±
20 ms
Reset time
ANSI DECAYING
[ ]
Tm
R
t
Is
I
res
×
−
=
1
2
,
±
5 % or
±
30 ms,
for char = ANSI-MI : R = 4.85
ANSI-VI : R = 21.6
ANSI-EI : R = 29.1
IEC DECAYING
[ ]
Tm
R
t
Is
I
res
×
−
=
1
2
,
±
5 % or
±
50 ms,
for char = IEC-NI : R = 9.7
IEC-VI : R = 43.2
IEC-EI : R = 58.2
IEC-LTI : R = 80
t
res
t
res
,
±
1 % or
±
20 ms
Repeatability
±
1 % or
±
20 ms
Overshoot time < 40 ms
Disengaging time < 50 ms
Figure 2.7.3-1 and Figure 2.7.3-4 show the operate and reset curves for the four IEC IDMTL curves with a time
multiplier of 1.
Figure 2.7.3-2 and Figure 2.7.3-3 show the ANSI operate and reset curves. 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.