GE L90 Instruction Manual page 47

2 PRODUCT DESCRIPTION
LINE CURRENT DIFFERENTIAL (87L)
Application: 2 or 3 terminal line, series compensated
line, tapped line, with charging current
compensation
Pickup current level: 0.20 to 4.00 pu in steps of 0.01
CT Tap (CT mismatch factor): 0.20 to 5.00 in steps of 0.01
Slope # 1: 1 to 50%
Slope # 2: 1 to 70%
Breakpoint between slopes: 0.0 to 20.0 pu in steps of 0.1
Zero-sequence current differential (87LG):
87LG pickup level: 0.05 to 1.00 pu in steps of 0.01
87LG slope: 1 to 50%
87LG pickup delay: 0.00 to 5.00 s in steps of 0.01
DTT: Direct Transfer Trip (1 and 3 pole) to
remote L90
Operating Time: 1.0 to 1.5 power cycles duration
Asymmetrical channel delay compensation using GPS:
asymmetry up to 10 ms
LINE CURRENT DIFFERENTIAL TRIP LOGIC
87L trip: Adds security for trip decision; creates 1
and 3 pole trip logic
DTT: Engaged Direct Transfer Trip (1 and 3
pole) from remote L90
DD: Sensitive Disturbance Detector to detect
fault occurrence
Stub bus protection: Security for ring bus and 1½ breaker
configurations
Open pole detector: Security for sequential and evolving
faults
PHASE/NEUTRAL/GROUND TOC
Current: Phasor or RMS
Pickup level: 0.000 to 30.000 pu in steps of 0.001
Dropout level: 97% to 98% of pickup
Level accuracy:
for 0.1 to 2.0  CT:
±0.5% of reading or ±0.4% of rated
(whichever is greater)
for > 2.0  CT: ±1.5% of reading > 2.0  CT rating
Curve shapes: IEEE Moderately/Very/Extremely
Inverse; IEC (and BS) A/B/C and Short
Inverse; GE IAC Inverse, Short/Very/
Extremely Inverse; I
(programmable); Definite Time (0.01 s
base curve)
Curve multiplier: Time Dial = 0.00 to 600.00 in steps of
0.01
Reset type: Instantaneous/Timed (per IEEE)
Operate at > 1.03  actual pickup
Timing accuracy:
±3.5% of operate time or ±½ cycle
(whichever is greater)
GE Multilin
PHASE/NEUTRAL/GROUND IOC
Pickup level:
Dropout level:
Level accuracy:
0.1 to 2.0  CT rating: ±0.5% of reading or ±0.4% of rated
> 2.0  CT rating
Overreach:
Pickup delay:
Reset delay:
Operate time:
Timing accuracy:
NEGATIVE SEQUENCE TOC
Current:
Pickup level:
Dropout level:
Level accuracy:
Curve shapes:
Curve multiplier (Time dial): 0.00 to 600.00 in steps of 0.01
Reset type:
Timing accuracy:
NEGATIVE SEQUENCE IOC
Current:
Pickup level:
Dropout level:
Level accuracy:
2
t; FlexCurves™
Overreach:
Pickup delay:
Reset delay:
Operate time:
Timing accuracy:
L90 Line Current Differential System
2.4 SPECIFICATIONS
0.000 to 30.000 pu in steps of 0.001
97 to 98% of pickup
(whichever is greater)
±1.5% of reading
<2%
0.00 to 600.00 s in steps of 0.01
0.00 to 600.00 s in steps of 0.01
<16 ms at 3  pickup at 60 Hz
(Phase/Ground IOC)
<20 ms at 3  pickup at 60 Hz
(Neutral IOC)
Operate at 1.5  pickup
±3% or ±4 ms (whichever is greater)
Phasor
0.000 to 30.000 pu in steps of 0.001
97% to 98% of pickup
±0.5% of reading or ±0.4% of rated
(whichever is greater)
from 0.1 to 2.0 x CT rating
±1.5% of reading > 2.0 x CT rating
IEEE Moderately/Very/Extremely
Inverse; IEC (and BS) A/B/C and Short
Inverse; GE IAC Inverse, Short/Very/
2
Extremely Inverse; I t; FlexCurves™
(programmable); Definite Time (0.01 s
base curve)
Instantaneous/Timed (per IEEE) and Lin-
ear
Operate at > 1.03  actual pickup
±3.5% of operate time or ±½ cycle
(whichever is greater)
Phasor
0.000 to 30.000 pu in steps of 0.001
97 to 98% of pickup
0.1 to 2.0  CT rating: ±0.5% of reading
or ±0.4% of rated (whichever is greater);
2.0  CT rating: ±1.5% of reading
 2%
0.00 to 600.00 s in steps of 0.01
0.00 to 600.00 s in steps of 0.01
< 20 ms at 3  pickup at 60 Hz
Operate at 1.5  pickup
±3% or ±4 ms (whichever is greater)
2
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