M-3520 Instruction Book
6–22
46IT Negative Sequence Overcurrent Inverse Time
VOLTAGE INPUTS:
None
CURRENT INPUTS:
Configuration C1 (MODIFIED)
TEST SETTINGS:
Pickup
P
Amps
(0.5 to 5.00)
1 Amp CT Rating
(0.1 to 1.00)
Standard Inverse Time Curves
1
:
Curve
C
(1 to 4)
Time Dial
TD
(0.5 to 11.0)
IEC Inverse Time Curves
1
:
IEC Curve
C
(5 to 8)
IEC Time Dial
TD
(0.05 to 1.10)
Programmed Outputs
Z
Output
(1 to 8)
Function 46 Inverse Time
Disable
Function 50
Disable
Function 51V, 79
Disable
1.
Disable functions as shown. Refer to Section 3.2, Configure Relay Data, for procedures.
2.
Confirm settings to be tested.
3.
Connect inputs in Configuration C1 (MODIFIED) designated previously. Refer to Section 6.4, Input
Configurations for configurations. The modification to C1 is to exchange Current source 2 and 3
connections. Configuration will be Phase B current from source 3 and Phase C current from
source 2.
■
■
■
■
■
NOTE
: For proper testing use current below 3 times CT rating.
4.
IEC Curve Testing
: Test current level may be chosen as a multiple of any level within the Pickup (
P
)
range. Calculate the operating time for the applied current and appropriate Time Dial (
TD
) setting
from the table below. Choose 4 or 5 test levels and calculate the operating times for each.
Standard Curve Testing
: The operating time will be read from Appendix D, Negative Sequence
Current Inverse Time Curves for the applied current and appropriate Time Dial (
TD
) setting. The
curve portions extending to lower than
P
current values are inactive and can be ignored.
5.
Time Test
: With output contacts connected to the timer, apply currents equal to the multiple of the
Inverse Time Pickup (
P
) chosen in Step 4, and start timing. The operating time will be as calculated
in step 4, ±3 cycles or ±5%.
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
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.
1
Either a Standard Curve or an IEC Curve must be selected.
Summary of Contents for M-3520
Page 1: ...Instruction Book M 3520 Intertie Protection Relay ...
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