Schweitzer Engineering Laboratories SEL-749M - Page 31

1.11
Date Code 20080918 Instruction Manual SEL-749M Relay
Introduction and Specifications
Specifications
Undervoltage (27)
Setting Range: Off, (0.60–1.00) • VNOM
Accuracy: ±5% of setting ±2 V
NOTE: VNOM is a setting (see the Main Settings (SET Command) of
the SEL-749M Settings Sheets at the end of Section 6 for setting
ranges).
Overvoltage (59)
Setting Range: Off, (1.00–1.20) • VNOM
Accuracy: ±5% of setting ±2 V
Underpower (37)
Setting Range: Off, 1–25000 kW primary
Accuracy: ±3% of setting ±5 W secondary
Reactive Power (VAR)
Setting Range: Off, (1–25000) kVAR primary
Accuracy: ±3% of setting ±5 VAR secondary
Power Factor (55)
Setting Range: Off, 0.05–0.99
Accuracy: ±5% of full scale for current ≥ 0.5 • FLA
Frequency (81)
Setting Range: Off, 55.0–65.0 Hz for FNOM = 60
Off, 45.0–55.0 Hz for FNOM = 50
Accuracy: ±0.1 Hz
NOTE: FNOM is a setting (see the Global Settings (SET G Command)
of the SEL-749M Settings Sheets at the end of Section 6 for setting
ranges).
Timers
Setting Range: See Section 6: Settings
Accuracy: ±0.5% of setting ±1/4 cycle
RTD Protection (Optional Using an SEL-2600 Module)
Measuring Range: –50° to +250°C
Update Time: <3 seconds
Up to 12 RTD inputs (SEL-2600 RTD module)
RTD Types: PT100, Ni100, Ni120, or CU10
Open and short RTD detection
Up to 500 m away, using fiber-optic cable
Trip and Alarm Temperatures
Setting Range: Off, 1°–250°C
Accuracy: <±2°C
Metering
Accuracies are specified at 20°C, nominal frequency, ac currents
within (0.2–20.0) • I
NOM
A secondary, and ac voltages within 50–
250 V secondary unless otherwise noted.
Motor Phase Currents: ±2% of reading, ±2°
3-Phase Average
Motor Current: ±2% of reading
3-Phase Average
Motor Load (%FLA): ±2% of reading
Current Imbalance (%): ±2% of reading
IG (Residual Current): ±3% of reading, ±2°
IN (Neutral Current): ±2% of reading, ±1°
3I2 Negative-Sequence
Current: ±3% of reading
System Frequency: ±0.1 Hz of reading for
frequencies within 44–66 Hz
Thermal Capacity: ±1% TCU
Time to Trip ±1 second
Line-to-Line Voltages: ±2% of reading, ±1° for voltages within
24–264 V
3-Phase Average Line-to-
Line Voltage:
±2% of reading for voltages within 24–
264 V
Line-to-Ground Voltages: ±2% of reading, ±1° for voltages within
24–264 V
3-Phase Average Line-to-
Ground Voltages:
±2% of reading for voltages within 24–
264 V
Voltage Imbalance (%): ±2% of reading for voltages within 24–
264 V
3V2 Negative-Sequence
Voltage:
±2% of reading for voltages within 24–
264 V
Real 3-Phase Power (kW): ±5% of reading for 0.10 < pf < 1.00
Reactive 3-Phase
Power (kVAR): ±5% of reading for 0.00 < pf < 0.90
Apparent 3-Phase
Power (kVA): ±2% of reading
Power Factor: ±2% of reading
RTD Temperatures: ±2°C
Courtesy of NationalSwitchgear.com