7SR11 & 7SR12 Performance Specification
ยฉ2017 Siemens Protection Devices Limited Chapter 3 Page 51 of 56
2.23 81 Under/over frequency
2.23.1 Reference
Parameter Value
Fs
Setting 43, 43.01โฆ 68 Hz
V
s
Guard
Guard Setting 35, 35.5, โฆ199.5, 200 V
Hyst
Hysteresis setting 0, 0.1โฆ 2%
td
Delay setting
0.00, 0.01
โฆ 20.0, 20.1โฆ 100.0, 101.โฆ1000, 1010 โฆ 10000 ,
10100 โฆ 14400 s
2.23.2 Operate and Reset Level
Attribute Value
F
op
Operate level
100 % F
s
, ยฑ 10mHz
Reset level
overfrequency
(100 % - hyst) xF
op,
ยฑ 10mHz
underfrequency
(100 % + hyst) xF
op,
ยฑ 10mHz
Repeatability
ยฑ 1 %
Variation -10 ยฐC to +55 ยฐC
โค 5 %
2.23.3 Operate and Reset Time
t
basic
Element basic
operate time
(for ROCOF
between 1 and
5.0 Hz/sec)
overfrequency
Typically < 110ms
Maximum < 150ms
underfrequency
Typically < 110ms
Maximum < 150ms
Element basic
operate time
(for ROCOF
between 0.1
and 1.0 Hz/sec)
overfrequency
Typically < 150ms
Maximum < 200ms
underfrequency
Typically < 150ms
Maximum < 200ms
t
op
Operate time following delay
t
basic
+ t
d
, ยฑ 1 % or ยฑ 10ms
Repeatability
ยฑ 1 % or ยฑ 10ms
Disengaging time
< 100 ms