Specifications; Protection - GE 845 Instruction Manual

SPECIFICATIONS

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Specifications

Protection

1–10
Harsh Environment Coating is a standard feature on all 8 Series units.
Advanced security is only available with advanced communications (1E, 1P, 2E). When the
advanced communications option is selected, the Ethernet port on the main CPU is
disabled.
To obtain the total operating time, i.e. from the presence of a trip condition to initiation of a
trip, add 8 ms output relay time to the operate times listed below.
TRANSFOMER PERCENT DIFFERENTIAL PROTECTION
Differential/Restraint Characteristic:......... Dual Slope, Dual Breakpoint
Minimum Pickup level:...................................... 0.05 to 1.00 x CT in steps of 0.01
Slope 1 range: ...................................................... 1 to 100% in steps of 1%
Slope 2 range: ...................................................... 1 to 100% in steps of 1%
Breakpoint 1:......................................................... 0.50 to 2.00 x CT in steps of 0.01
Breakpoint 2:......................................................... 2.00 to 30.00 x CT in steps of 0.01
nd
2 harmonic inhibit level:.............................. 0.1 to 40.0% in steps of 0.1%
nd
2 harmonic inhibit mode: ........................... Per-phase, Average, 2-out-of-3, 1-out-of-3
th
5 harmonic inhibit level:............................... 1.0 to 40.0% in steps of 0.1%
Dropout level: ....................................................... 97 to 98% of Pickup
Operate time:........................................................ < 16/22 ms at >3 x Pickup @60Hz (harmonic inhibits
Level accuracy:.................................................... ± 0.5% at reading current, or ±1% of rated
TRANSFORMER OVERLOAD
Operating Parameter: ...................................... Winding 1, 2, 3 loads
Pickup level:........................................................... 50 to 300% in steps of 1%
Dropout level: ....................................................... 97 to 98% of Pickup
Level Accuracy:.................................................... Per current input
Operate time:........................................................ <25 ms at >3 x Pickup at 60 Hz,
Timer Accuracy: .................................................. ±3% of delay setting or ± ¼ cycle (whichever is greater) from
INSTANTANEOUS PHASE DIFFERENTIAL FUNCTION
Pickup level:........................................................... 3.00 to 30.00 per unit in steps 0.01
Dropout level: ....................................................... 97 to 98% of Pickup
Operate time:........................................................ <12 ms at >3 x Pickup@60Hz
disabled/enabled)
< 18/26 ms at >3 x Pickup @50Hz (harmonic inhibits
disabled/enabled)
<30 ms at >3 x Pickup at 50 Hz
pickup to operate
<15 ms at >3 x Pickup@50Hz
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: INTRODUCTION