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5–21
Testing – 5
51N Inverse Time Residual Overcurrent
VOLTAGE INPUTS:
None
CURRENT INPUTS:
C1 (modified)
TEST SETTINGS:
51N Pickup
P Amps
(0.5 to 6)
1 Amp CT Rating
(0.1 to 1.2)
Standard Inverse Time Curves:
1
Curve
C
(1-4)
Time Dial
TD
(.5 to 11)
IEC Inverse Time Curves:
1
(inverse/very inverse/extremely inverse/long time inverse)
IEC Curve
C
(5 to 8)
IEC Time Dial
TD
(.05 to 1.1)
Programmed Outputs
Z OUT
(1 or 2)
1
Either a standard curve or an IEC curve must be selected.
1.
Disable functions as shown. Refer to Section 3.2, Setpoints and Time Settings, for procedures.
2.
Confirm settings to be tested.
3.
Connect current inputs in Configuration C1 (modified) designated previously. See Section 5.1,
Equipment/Test Setup for configuration. The modification to C1 is to set all three currents to
phase angles 0°. In this configuration, the applied value of
I
N
is equal to the sum of the 3-phase
currents
I
N
=(
I
a
+
I
b
+
I
c
).
4.
Refer to Appendix D . Calculate test times for levels represented on the graphs. Choose 4 or 5 test
levels and calculate test times for each. For IEC curves, the following formulas can be used:
Curve 5
t=TD x
0.14
M
0.02
- 1
[
]
Curve 6
t=TD x
13.5
M - 1
[
]
Curve 7
t=TD x
80
M
2
- 1
[
]
Curve 8
t=TD x
120
M - 1
[
]
IEC Class A
Standard Inverse
IEC Class B
Very Inverse
IEC Class C
Extremely Inverse
IEC Class D
Long Time Inverse
t = time in seconds TD = Time Dial setting M = current in multiples of pickup
5.
Time Test
: With output contacts connected to the timer, apply input current used in calculations
from step 4 and start timing. The operating time will be
&
3 cycles or
&
10%* of calculated time
(refer to Appendix D,
Inverse Time Curves
). Repeat this step for each test level chosen. The
tested points verify the operation of this function.
6.
If testing is complete, enable any functions disabled for this test. If further testing is desired,
check the proper functions to disable for the next test and continue from this point.
*The specified timing accuracy is applicable for currents above three times the pickup value.
Summary of Contents for Syncrocloser M-3410A
Page 1: ...Instruction Book M 3410A Intertie Generator Protection Relay ...
Page 39: ...xiv M 3410A Instruction Book This Page Left Intentionally Blank ...
Page 71: ...M 3410A Instruction Book 2 28 This Page Left Intentionally Blank ...
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Page 161: ...1 3 A B C M 3410A Instruction Book 4 40 This Page Left Intentionally Blank ...
Page 223: ...M 3410A Instruction Book F 2 This Page Left Intentionally Blank ...