ERL F-PRO 5100, User Manual

Page: 58 / 192

4 Protection Functions and Specifications
4-12 F-PRO 5100 User Manual D02416R04.00
81 Frequency
The relay has four frequency devices available. Each frequency element can be
set to operate either at a fixed level of under-frequency, a fixed level of over-
frequency or at a rate of change level (df/dt). The df/dt function can be set to
operate for a positive rate of change or a negative rate of change. Each frequen-
cy element has a definite time delay setting to create a time delayed output. A
fixed level of positive sequence voltage of 0.25 pu or 5 volts whichever is
greater provides an undervoltage inhibit on each element.
Four frequency elements are provided, settable from over/under frequency,
fixed level to rate of change.
T
O
Frequency (Hz)
Figure 4.11: Frequency Fixed Level
T
O
df/dt (Hz/s)
Figure 4.12: Frequency Rate of Change
81 Over/Under Frequency
81-1 Disabled/Fixed Level/Rate of Change
Pickup 50.000 to 59.995 or 60.005 to 70.000 (fixed level)
-10.0 to -0.1 or 0.1 to 10.0 (rate of change)
Pickup Delay 0.05 to 99.99 seconds (fixed level)
0.20 to 99.99 seconds (rate of change)
81-2 Disabled/Fixed Level/Rate of Change
Pickup 50.000 to 59.995 or 60.005 to 70.000 (fixed level)
-10.0 to -0.1 or 0.1 to 10.0 (rate of change)
Pickup Delay 0.05 to 99.99 seconds (fixed level)
0.20 to 99.99 seconds (rate of change)
81-3 Disabled/Fixed Level/Rate of Change
Pickup 50.000 to 59.995 or 60.005 to 70.000 (fixed level)
-10.0 to -0.1 or 0.1 to 10.0 (rate of change)
Pickup Delay 0.05 to 99.99 seconds (fixed level)
0.20 to 99.99 seconds (rate of change)
81-4 Disabled/Fixed Level/Rate of Change
Pickup 50.000 to 59.995 or 60.005 to 70.000 (fixed level)
-10.0 to -0.1 or 0.1 to 10.0 (rate of change)
Pickup Delay 0.05 to 99.99 seconds (fixed level)
0.20 to 99.99 seconds (rate of change)