Areva MiCOM P921 - Page 65

Technical Guide P92x/EN TD/E11
Technical Data
MiCOM P921-P922-P923 Page 19/30
3.6 Under/overfrequency (ANSI codes 81U/81O) only P922 & P923
Setting Range Step Size
F1 threshold Fn – 10Hz, Fn + 10Hz 0.01 Hz
tF1 (definite time delay) 0 – 599s 0.01s
F2 threshold Fn – 10Hz, Fn + 10Hz 0.01 Hz
tF2 (definite time delay) 0 – 599s 0.01s
F3 threshold Fn – 10Hz, Fn + 10Hz 0.01 Hz
tF3 (definite time delay) 0 – 599s 0.01s
F4 threshold Fn – 10Hz, Fn + 10Hz 0.01 Hz
tF4 (definite time delay) 0 – 599s 0.01s
F5 threshold Fn – 10Hz, Fn + 10Hz 0.01 Hz
tF5 (definite time delay) 0 – 599s 0.01s
F6 threshold Fn – 10Hz, Fn + 10Hz 0.01 Hz
tF6 (definite time delay) 0 – 599s 0.01s
Where : Fn : nominal frequency
3.7 Rate of change of frequency (ANSI codes 81R) only P923
3.7.1 Threshold settings
Setting Range Step Size
df/dt1 threshold –10 Hz/s, +10 Hz/s 0.1 Hz/s
df/dt2 threshold –10 Hz/s, +10 Hz/s 0.1 Hz/s
df/dt3 threshold –10 Hz/s, +10 Hz/s 0.1 Hz/s
df/dt4 threshold –10 Hz/s, +10 Hz/s 0.1 Hz/s
df/dt5 threshold –10 Hz/s, +10 Hz/s 0.1 Hz/s
df/dt6 threshold –10 Hz/s, +10 Hz/s 0.1 Hz/s
3.7.2 Integration time
Setting Range Step Size
cycle number 1 – 200 1 cycle
3.7.3 Validation number of protection
Setting Range Step Size
Validation 2 or 4 2