Specifications

7SR242 Duobias Performance Specification
©2010 Siemens Protection Devices Limited Chapter 3 - Page 38 of 45
2.14 81Under/Over Frequency
2.14.1 Reference
Parameter Value
F
s
Setting 40, 40.01… 69.99 Hz
Hyst
Hysteresis setting 0, 0.1… 80%
td
Delay setting
0.00, 0.01… 20.0, 20.1… 100.0, 101.…1000, 1010 … 10000 ,
10100 … 14400 s
2.14.2 Operate and Reset Level
Attribute Value
F
op
Operate level
100 % F
s
, r 10mHz
overfrequency
(100 % - hyst) xF
op,
r 10mHz
Reset level
underfrequency
(100 % + hyst) xF
op,
r 10mHz
Repeatability
r 1 %
Variation -10 °C to +55 °C
d 5 %
2.14.3 Operate and Reset Time
Attribute Value
Typically  110ms
overfrequency
Maximum  150ms
Typically  110ms
t
basic
Element basic
operate time
(for ROCOF
between 0.1
and 5.0 Hz/sec)
underfrequency
Maximum  150ms
t
op
Operate time following delay
t
basic
+ t
d
, r 1 % or r 10ms
Repeatability
r 1 % or r 10ms
Disengaging time
 100 ms