81 Frequency Protection – "f>" or "f<"
Reference
Parameter
Value
f
set
Setting
43 to 68 Hz, Δ 0.01 Hz
f
Applied frequency (for operate time)
Hysteresis
Hysteresis
0 to 2 %, Δ 0.1 %
t
delay
Delay setting
0 to 20 s, Δ 0.01 s
20 to 100 s, Δ 0.1 s
100 to 1000 s, Δ 1 s
1000 to 10000 s, Δ 10 s
1000 to 14400 s, Δ 100 s
Operate and Reset Level
Attribute
Value
f
op
Operate level
f
set
: ± 10 MHz
Reset level
Over frequency
(100 % - hysteresis) ⋅ f
op
± 10 mHz
Under frequency
(100 % + hysteresis) ⋅ f
op
± 10 mHz
Repeatability
± 1 %
Variation IEC
60255-1
-10 °C to +55 °C
≤ 5 %
f
rated
± 5 %
≤ 5 %
Operate and Reset Time
Attribute
Value
t
basic
Element basic
operate time (for
ROCOF between 0.1
and 5 Hz/s)
Over frequency
Typically < 110 ms
Maximum < 150 ms
Under frequency
Typically < 110 ms
Maximum < 150 ms
t
op
Operate time following delay
t
basic
+ t
delay
± 1 % or ± 10 ms
Repeatability
± 1 % or ± 10 ms
Disengaging time
< 100 ms
10.28
Technical Data
10.28 81 Frequency Protection – "f>" or "f<"
Reyrolle 7SR5, Transformer Protection Device, Device Manual
495
C53000-G7040-C015-1, Edition 11.2019