Siemens 7SR12 Argus - Time Delayed Derived Earth Fault; Reference; Operate and Reset Level; Operate and Reset Time

7SR11 & 7SR12 Performance Specification
©2017 Siemens Protection Devices Limited Chapter 3 Page 39 of 56
2.14 51N Time Delayed Derived Earth Fault
2.14.1 Reference
Parameter Value
Is
Setting
0.05, 0.6… 2.5 xIn
char
Characteristic setting
IEC-NI, -VI, -EI, -LTI;
ANSI-MI, -VI, -EI; DTL
Tm
Time Multiplier setting
IEC: 0.025, 0.030… 1.6
ANSI: 0.025, 0.030… 1.6 1.7… 5, 6… 15
t
d
Delay setting 0, 0.01… 20 s
t
res
Reset setting ANSI DECAYING, 0, 1… 60 s
I
Applied Current
(for operate time)
IDMTL 2 to 20 x Is
DTL 5 x Is
2.14.2 Operate and Reset Level
Attribute Value
I
op
Operate level
105 % Is, ± 4 % or ± 1% In
Reset level
≥ 95 % I
op
Repeatability
± 1 %
Variation
-10 °C to +55 °C
≤ 5 %
f
nom
± 5 %
≤ 5 %
2.14.3 Operate and Reset Time
Attribute Value
Starter operate time (≥ 2xIs)
30 ms, ± 20ms
t
op
Operate time
char = IEC-NI,
IEC-VI,
IEC-EI,
IEC-LTI
[
]
Tm
K
t
Is
I
op
×
−
=
1
α
, ± 5 % absolute 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
[ ]
TmB
A
t
P
Is
I
op
×








+
−
=
1
, ± 5 % absolute 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 ± 20ms
Reset time ANSI DECAYING
[ ]
Tm
R
t
Is
I
res
×
−
=
1
2
, ± 5 % absolute or ± 30 ms,
for char = ANSI-MI : R = 4.85
ANSI-VI : R = 21.6
ANSI-EI : R = 29.1