Schweitzer Engineering Laboratories, Inc.
SEL-787-3, -4 Data Sheet
29
RTD Short-Circuit
Detection: <–50°C
RTD Types:
Pt100, Ni100, Ni120, Cu10
RTD Lead Resistance:
25 ohm max. per lead
Update Rate:
<3 s
Noise Immunity on RTD
Inputs:
To 1.4 Vac (peak) at 50 Hz or greater
frequency
RTD Trip/Alarm Time
Delay:
Approx. 6 s
Synchronism Check (25)
Pickup Range, Secondary
Voltage:
0.00–300.00 V
Pickup Accuracy, Secondary
Voltage:
±1% plus ±0.5 volts (over the range of
2.00–300.00 V)
Slip Frequency Pickup
Range:
0.05 Hz–0.50 Hz
Slip Frequency Pickup
Accuracy:
±0.02 Hz
Phase Angle Range:
0–80°
Phase Angle Accuracy:
±4°
Station Battery Voltage Monitor
Operating Range:
0–350 Vdc (300 Vdc for UL purposes)
Pickup Range:
20.00–300.00 Vdc
Pickup Accuracy:
±2% of setting plus ±2 Vdc
Timers
Setting Range:
Various
Accuracy:
±0.5% of setting plus ±1/4 cycle
Metering Accuracy
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.
Phase Currents
Magnitude Accuracy:
±1.0% (I
NOM
= 1 A or 5 A)
Phase Accuracy:
±1.0
(I
NOM
= 5 A), ±1.0
at 0.5–20.0
times I
NOM
(I
NOM
= 1 A), ±2.5
at
0.2–0.5 times I
NOM
(I
NOM
= 1 A)
Differential Quantities:
±5% of reading plus ±0.1 A (5 A nominal),
±0.02 A (1 A nominal)
Current Harmonics:
±5% of reading plus ±0.1 A (5 A nominal),
±0.02 A (1 A nominal)
I1 Positive-Sequence
Current:
±2% of reading
IG (Residual Current):
±2% of reading, ±2° (±5.0° at 0.2–0.5 A
for relays with I
NOM
= 1 A)
IN (Neutral Current):
±1% of reading, ±1° (±2.5° at 0.2–0.5 A
for relays with I
NOM
= 1 A)
3I2 Negative-Sequence
Current:
±2% of reading
System Frequency:
±0.01 Hz of reading for frequencies
within 15–70 Hz (requires ac voltage
inputs, V1 > 60 V)
Line-to-Line Voltages:
±1% of reading, ±1° for voltages
within 24–264 V
Line-to-Ground Voltages:
±1% of reading, ±1° for voltages
within 24–264 V
Voltage Harmonics:
±5% of reading plus ±0.5 V
V1 Positive-Sequence
Voltage:
±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):
±3% of reading for 0.10 < pf < 1.00
Reactive 3-Phase
Power (kVAR):
±3% of reading for 0.00 < pf < 0.90
Apparent 3-Phase
Power (kVA):
±3% of reading
Power Factor:
±2% of reading for 0.86
pf
1
RTD Temperatures:
±2°C
Synchrophasor Accuracy
Maximum Message Rate
Nominal 60 Hz System:
60 messages per second
Nominal 50 Hz System:
50 messages per second
The following are the accuracy specifications for voltages and currents
for the SEL-787-3E and SEL-787-3S models. Note that the
SEL-787-4X model does not track frequency, so the accuracy
specifications are only applicable when the applied signal frequency
equals FNOM.
Accuracy for Voltages
Level 1 compliant as specified in IEEE C37.118 under the following
conditions for the specified range.