Distance Relay Setting Examples
GARD 8000 Distance Relay
RFL Electronics Inc.
Description Range
Units
Step
Actual
81 UNDFREQ2
Enables trip by Underfrequency, step 2.
Disable -
Enable - 1
Disable
81 UNDFREQ3
Enables trip by Underfrequency, step 3.
Disable -
Enable
- 1
Disable
81 OVERFREQ1
Enables trip by Overfrequency, step 1.
Disable -
Enable
- 1
Disable
81 OVERFREQ2
Enables trip by Overfrequency, step 2.
Disable -
Enable
- 1
Disable
81 OVERFREQ3
Enables trip by Overfrequency, step 3.
Disable -
Enable - 1
Disable
81 FREQCHG1
Enables trip by Rate-of-change of Frequency, step 1.
Disable -
Enable - 1
Disable
81 FREQCHG2
Enables trip by Rate-of-change of Frequency, step 2.
Disable -
Enable
- 1
Disable
81 FREQCHG3
Enables trip by Rate-of-change of Frequency, step 3.
Disable -
Enable
- 1
Disable
8.1.6
REACH SETTINGS
Pilot scheme settings will be discussed in further detail below. The following is an example of a basic
stepped distance setting with Z1 set to 80% of line impedance, Z2 set to 120%, Z3 set to 200% and Z4
set to 50% in the reverse direction. Z1, Z2 and Z3 are set for trip (after corresponding time delay).
Zone 4 is enabled for measurement only, intended for use as a fault trigger, but not trip.
Zone 1 reach
80% of ZL1 = 0.8 · 4.13 = 3.30
Time delay = 0
Zone 2 reach
120% of ZL1 = 1.2 · 4.13 = 4.96
Time delay = 300 ms (0.3 s)
Zone 3 reach
200% of ZL1 = 2 · 4.13 = 8.26
Time delay = 800 ms (0.8 s)
Zone 4 reach (reverse, used for indication only in this stepped distance scheme)
50% of ZL1 = 0.5 · 4.13 = 2.07
August 1, 2009
8-8
973.334.3100