GE 850 - Page 34

1–24 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
SPECIFICATIONS CHAPTER 1: INTRODUCTION
SOTF (SWITCH ON TO FAULT)
Number of Elements: ........................................6 (3 per Breaker)
Pickup Threshold:................................................0.050 to 10.000 pu of CT in steps of 0.001
Pickup Level Accuracy: ....................................0.1 to 2.0 x CT rating: ±0.5% of reading or ±1% of rated
(whichever is greater)
> 2.0 x CT rating: ±1.5% of reading
Pickup Level: .........................................................0.05 to 1.00 x VT in steps of 0.01
Level Accuracy: ................................................... ±0.5% of reading from 10 to 240 V
Pickup Delay:........................................................ 0.000 to 600.000 s in steps of 0.01
Time Accuracy:....................................................±3% or ±35 ms, whichever is greater
Operate Time: ......................................................<10 ms @ 60Hz
TIMED UNDERVOLTAGE - TIMED UV (27T)
Operating Parameter: ......................................[VA, VB, VC] or [VA, VB, VC] (Phasor)
Minimum Voltage: ..............................................0.00 to 1.50 (VT) in steps of 0.01 VT
Pickup Level: .........................................................0.00 to 1.50 (VT) in steps of 0.01 VT
Dropout Level:......................................................102.0% to 150.0% of PKP in steps of 0.1% PKP
Level Accuracy: ................................................... ±0.5% of reading from 10 to 240 V
Phases required for operation:.....................Any one, Any two, All three
Curve Limit:............................................................0.00 to 1.50 (VT) in steps of 0.01 VT
Curve Time: ...........................................................0.000 – 600000.000 s in steps of 0.001s
Dropout Time Delay:.........................................0.000 – 600000.000 s in steps of 0.001s
Pickup Accuracy: ................................................Per phase voltage input channel error
Dropout Accuracy:.............................................Per phase voltage input channel error
Curve Timing Accuracy:.................................. at < 0.90 x pickup: ± 3.5% of operate time or ± ½ cycle
(whichever is greater) from pickup to operate
THERMAL OVERLOAD (49)
Operating Parameter: ...................................... RMS current
Pickup Level: .........................................................0.050 to 30.000 x CT in steps of 0.001 x CT
Alarm Level:...........................................................70.0 to 110.0% in steps 0.1%
Heat Time Constant (τ
H
):................................. 3.0 to 600.0 min in steps of 0.1 min
Cool Time Constant (τ
C
): ..................................1.00 to 6.00 x τ
H
in steps of 0.01 x τ
H
Current Level Accuracy:..................................For 0.1 to 2.0 x CT: ± 0.5% of reading or ± 0.4% of rated
(whichever is greater)
For > 2.0 x CT: ± 1.5% of reading
Operate Time: ......................................................< 45 ms at 60 Hz (from 0 to 120 x pickup)
< 50 ms at 50 Hz (from 0 to 120 x pickup)
UNDERCURRENT (37)
Operating Parameter: ...................................... Per-phase current Ia, Ib, Ic (Phasor)
Trip/Alarm Pickup Level:..................................0.05 to 0.95 x CT in steps of 0.01 x CT
Dropout Level:......................................................102 to 103% of Pickup
Trip/Alarm Delay:................................................0.00 to 180.00 s in steps of 0.01 s
Pickup Accuracy: ................................................For 0.05 to 2.0 x CT: ±0.5% of reading or ±0.4% of rated,
whichever is greater
Operate Time: ......................................................<45 ms at 60 Hz,<50 ms at 50 Hz
Timer Accuracy:.................................................. ±3% of delay setting or ± 2 power cycles (whichever is
greater) from pickup to operate
Stages: .....................................................................Trip and Alarm
No. of Elements:...................................................3