CHAPTER 1: INTRODUCTION
SPECIFICATIONS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
1–9
The graph shows the trip time error with respect to the ratio of cable load and thermal
model pickup setting. With a smaller I/Ipkp ratio, the time error tends to be higher, as
accumulated through the logarithmic formula, the measurement error, and the time of
measurement. For higher I/Ipkp ratios, the time to trip is substantially more accurate. Each
point on the graph represents a trip time error, with the I/Ipkp ratio kept constant during
the test.
PHASE/AUXILIARY UNDERVOLTAGE (27P, 27X)
Minimum Voltage:...............................................Programmable from 0.00 to 1.25 x VT in steps of 0.01
Pickup Level:..........................................................0.00 to 1.25 x VT in steps of 0.01
Dropout Level: ......................................................101 to 104% of pickup
Curve: .......................................................................Definite Time, Inverse Time
Time Delay:............................................................0.1 to 600.0 s in steps of 0.1
Operate Time:.......................................................Time delay ±30 ms @ 60Hz (V < 0.85 x PKP)
Time delay ±40 ms @ 50Hz (V < 0.85 x PKP)
Time Delay Accuracy:.......................................±3% of expected time or 1 cycle, whichever is greater
Level Accuracy:....................................................Per voltage input
PHASE/AUXILIARY/NEUTRAL/NEGATIVE SEQUENCE OVERVOLTAGE (59P, 59X, 59N, 59_2)
Pickup Level:..........................................................0.00 to 1.25 x VT in steps of 0.01
Dropout Level: ......................................................96 to 99% of pickup
Time Delay:............................................................0.1 to 600.0 s in steps of 0.1
Operate Time:.......................................................Time delay ±35 ms @ 60Hz (V > 1.1 x PKP)
Time delay ±40 ms @ 50Hz (V > 1.1 x PKP)
Time Delay Accuracy:.......................................0 to 1 cycle
Level Accuracy:....................................................Per voltage input
UNDERFREQUENCY (81U)
Minimum Voltage:...............................................0.00 to 1.25 x VT in steps of 0.01
Pickup Level:..........................................................40.00 to 70.00 Hz in steps of 0.01
Dropout Level: ......................................................0.03 Hz
Time Delay:............................................................0.0 to 600.0 s in steps of 0.1
Time Delay Accuracy:.......................................0 to 6 cycles (Time Delay selected)
Operate Time:.......................................................Typically 10 cycles @ 0.1Hz/s change
Level Accuracy:....................................................±0.01 Hz
OVERFREQUENCY (81O)
Minimum Voltage:...............................................0.3 x VT
Pickup Level:..........................................................40.00 to 70.00 Hz in steps of 0.01
Dropout Level: ......................................................Pickup -0.03 Hz
Time Delay:............................................................0.0 to 600.0 s in steps of 0.1
Time Delay Accuracy:.......................................0 to 6 cycles (Time Delay selected)
Operate Time:.......................................................Typically 10 cycles @ 0.1Hz/s change
Level Accuracy:....................................................±0.01 Hz
Metering
NOTE
NOTE:
Full scale for CT Input is 3 x CT
PARAMETER
ACCURACY
RESOLUTION RANGE
3-Phase Real Power (MW)
±
1% of full scale
0.1 MW
±
3000 MW
3-Phase Reactive Power (Mvar)
±
1% of full scale
0.1 Mvar
±
3000 Mvar
3-Phase Apparent Power (MVA)
±
1% of full scale
0.1 MVA
3000 MVA
Power Factor
±
0.05
0.01
-0.99 to 1.00
Frequency
±
0.05 Hz
0.01 Hz
40.00 to 70.00 Hz
