CHAPTER 2: PRODUCT DESCRIPTION SPECIFICATIONS
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 2-35
2
Curve shapes: IEEE Moderately/Very/Extremely Inverse; IEC (and BS) A/B/C and Short Inverse; GE IAC Inverse,
Short/Very/ Extremely Inverse; I
2
t; FlexCurvesâ„¢ (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) and Linear
Curve timing accuracy
at 1.03 to 20 x pickup: ±3.5% of operate time or ±½ cycle (whichever is greater) from pickup to operate
NEGATIVE SEQUENCE IOC
Current: Phasor
Pickup level: 0.020 to 30.000 pu in steps of 0.001
Dropout level: 97 to 98% of pickup
Level accuracy: 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
Overreach: <2%
Pickup delay: 0.00 to 600.00 s in steps of 0.01
Reset delay: 0.00 to 600.00 s in steps of 0.01
Operate time: <20 ms at 3 × pickup at 60 Hz
Timer accuracy: ±3% of operate time or ±1/4 cycle (whichever is greater)
PHASE DIRECTIONAL OVERCURRENT
Relay connection: 90° (quadrature)
Quadrature voltage: ABC phase seq.: phase A (V
BC
), phase B (V
CA
), phase C (V
AB
); ACB phase seq.: phase A (V
CB
), phase
B (V
AC
), phase C (V
BA
)
Polarizing voltage threshold: 0.004 to 3.000 pu in steps of 0.001
Current sensitivity threshold: 0.05 pu
Characteristic angle: 0 to 359
° in steps of 1
Angle accuracy: ±2°
Operation time (FlexLogic operands):
Tripping (reverse load, forward fault): <12 ms, typically
Blocking (forward load, reverse fault): <8 ms, typically
NEUTRAL DIRECTIONAL OVERCURRENT
Directionality: Co-existing forward and reverse
Polarizing: Voltage, Current, Dual, Dual-V, Dual-I
Polarizing voltage: V_0 or VX
Polarizing current: IG
Operating current: I_0
Level sensing: 3 × (|I_0| – K × |I_1|), IG
Restraint, K: 0.000 to 0.500 in steps of 0.001
Characteristic angle: –90 to 90° in steps of 1
Limit angle: 40 to 90° in steps of 1, independent for forward and reverse
Angle accuracy: ±2°
Offset impedance: 0.00 to 250.00 Ω in steps of 0.01
Pickup level: 0.002 to 30.000 pu in steps of 0.01
Dropout level: 97 to 98%
Operation time: <16 ms at 3 × pickup at 60 Hz
NEGATIVE SEQUENCE DIRECTIONAL OC
Directionality: Co-existing forward and reverse
Polarizing: Voltage
Polarizing voltage: V_2
Operating current: I_2
Level sensing:
Zero-sequence: |I_0| – K × |I_1|
Negative-sequence: |I_2| – K × |I_1|
Restraint, K: 0.000 to 0.500 in steps of 0.001
Characteristic angle: 0 to 90° in steps of 1