CHAPTER 2: PRODUCT DESCRIPTION SPECIFICATIONS
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL 2-21
2
NEUTRAL VOLTAGE UNBALANCE
Operation: compensated for inherent bank and system unbalance
Auto-setting: on demand from keypad
Number of elements: 1 per VT bank, maximum of 3
Compensating factor: 0.7500 to 1.2500 in steps of 0.0001
Number of trip/alarm stages: 4 with individual timers
Pickup threshold: 0.001 to 1.000 pu of nominal of the bank neutral point VT in steps of 0.001
Slope: 0 to 10% in steps of 0.1
Pickup level accuracy: 0.003 pu for <10 VT mismatch between phase and neutral VT
Hysteresis: 3% or 0.001 pu whichever is greater
Pickup delay: 0 to 600.00 s in steps of 0.01
Timer accuracy: ±3% of operate time or ±35 ms, whichever is greater
Operate time: <35 ms at 60 Hz
PHASE UNDERVOLTAGE
Pickup level: 0.004 to 3.000 pu in steps of 0.001
Dropout level: 102 to 103% of pickup
Level accuracy: ±0.5% of reading from 10 to 208 V
Curve shapes: GE IAV Inverse;
Definite Time (0.1 s base curve)
Curve multiplier: Time dial = 0.00 to 600.00 in steps of 0.01
Curve timing accuracy at <0.90 x pickup:
±3.5% of operate time or ±1/2 cycle (whichever is greater) from pickup to operate
Operate time: <30 ms at 0.9 pickup at 60 Hz for Definite Time mode
BANK OVERVOLTAGE
Operation: per phase, 3 stages of definite-time, 1 stage of inverse-time
Application: grounded and ungrounded banks
Number of elements: 1 per VT bank, maximum of 3
Pickup threshold: 0.800 to 2.000 pu of bus voltage in steps of 0.001, per phase
Pickup level accuracy: 0.002 pu for operating voltage <70 V
Hysteresis: 0.02 pu
Pickup delay: 0 to 600.00 s in steps of 0.01
Curve: any user-programmable FlexCurve
Timer accuracy: ±3% of operate time or ±35 ms, whichever is greater
Operate time: <35 ms at 60 Hz
PHASE OVERVOLTAGE
Voltage: Phasor only
Pickup level: 0.004 to 3.000 pu in steps of 0.001
Dropout level: 97 to 98% of pickup
Level accuracy: ±0.5% of reading from 10 to 208 V
Pickup delay: 0.00 to 600.00 in steps of 0.01 s
Operate time: <30 ms at 1.10 × pickup at 60 Hz
Timer accuracy: ±3% of operate time or ±1/4 cycle (whichever is greater)
NEUTRAL OVERVOLTAGE
Pickup level: 0.004 to 3.000 pu in steps of 0.001
Dropout level: 97 to 98% of pickup
Level accuracy: ±0.5% of reading from 10 to 208 V
Pickup delay: 0.00 to 600.00 s in steps of 0.01 (definite time) or user-defined curve
Reset delay: 0.00 to 600.00 s in steps of 0.01
Curve timing accuracy at >1.1 pickup: ±3.5% of operate time or ±1 cycle (whichever is greater) from pickup to operate
Operate time: <30 ms at 1.10 pickup at 60 Hz
AUXILIARY OVERVOLTAGE
Pickup level: 0.004 to 3.000 pu in steps of 0.001
Dropout level: 97 to 98% of pickup