BECKWITH ELECTRIC M-3425, Instruction Book

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–6–
M-3425 Generator Protection Relay
STANDARD PROTECTIVE FUNCTIONS ( cont.)
Device Setpoint
Number Function Ranges Increment Accuracy †
RMS Overvoltage
Pickup #1, #2 5 to 180 V 1 V ! 0.5 V or ! 0.5%
! 0.8 V to ! 0.75%*
Time Delay #1, #2 1 to 8160 Cycles 1 Cycle ! 1 Cycle or ! 1%**
*When both RMS and Line-Ground to Line-Line is selected.
**When RMS (total waveform) is selected, timing accuracy is +20 cycles or ! 1%.
RMS Overvoltage, Neutral
Pickup #1, #2 5.0 to 180.0 V 0.1 V ! 0.5 V to ! 0.5%
Time Delay #1, #2 1 to 8160 Cycles 1 Cycle
!
1 Cycle or
!
1%
VT Fuse-Loss Detection
A VT fuse-loss condition is detected by using the positive and negative sequence components
of the voltages and currents. VT fuse-loss output can be initiated from internally generated logic
or from input contacts.
Time Delay 1 to 8160 Cycles 1 Cycle
!
1 Cycle or
!
1%
Out of Step (mho characteristic)
Circle Diameter 0.1 to 100.0
Ω
0.1
Ω
! 0.1
Ω
or 5%
(0.5 to 500.0
Ω
) (
!
0.5
Ω
or 5%)
Offset –100.0 to 100.0
Ω
0.1
Ω
!
0.1
Ω
or 5%
(–500.0 to 500.0
Ω
) ( ! 0.5
Ω
or 5%)
Impedance Angle 0° to 90° 1°
!
1°
Blinder 0.1 to 50.0
Ω
0.1
Ω
!
0.1
Ω
or 5%
(0.5 to 250.0
Ω
) ( ! 0.5
Ω
or 5%)
Time Delay 1 to 8160 Cycles 1 Cycle
!
1 Cycle or
!
1%
Trip on mho Exit Enable/Disable
Pole Slip Counter 1 to 20 1
Pole Slip Reset 1 to 8160 Cycles 1 Cycle
!
1 Cycle or
!
1%
Frequency
Pickup #1,#2,#3,#4 50.00 to 67.00 Hz 0.01 Hz ! 0.02 Hz
40.00 to 57.00 Hz*
Time Delay #1–#4 2 to 65,500 Cycles 1 Cycle ! 2 Cycles or ! 1%
The pickup accuracy applies to 60 Hz models at a range of 57 to 63 Hz, and to 50 Hz models at a range of 47 to
53 Hz. Beyond these ranges, the accuracy is
! 0.1 Hz.
* This range applies to 50 Hz nominal frequency models.
†
Select the greater of these accuracy values. Values in parentheses apply to 1 A CT secondary rating.
59
59N
60
FL
81
78