M-3520 Instruction Book
6–26
51V Inverse Time Overcurrent, Phase
VOLTAGE INPUTS:
None
CURRENT INPUTS:
C1
TEST SETTINGS:
Pickup
P
Amps
(0.50 to 12.00)
1 Amp CT Rating
(0.10 to 2.40)
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 50, 67
Disable
1.
Disable functions as shown. Refer to Section 3.2, Configure Relay Data, for procedures.
2.
Confirm settings to be tested.
3.
Connect current inputs in Configuration C1 designated previously. Refer to Section 6.4, Input
Configurations, for configurations.
4.
Refer to Appendix D. Calculate test times for levels represented on the graphs. It is suggested that
4 or 5 test levels be chosen.
5.
Time Test
:
With output contacts connected to the timer, apply current used in calculations from step
4 and start timing. The operating time will be ±3 cycles or 5% of calculated time. Repeat this step for
each test level chosen. The tested points verify the operation of this function.
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.
Voltage Control Test
: Input voltages at least 5% under the Voltage Control setting V.
a. With output contacts connected to the timer, apply current equal to the chosen test level
calculated in step 4 on phase A, and start timing. The operating time will be as read from the
appropriate Inverse Curve Family and
K
(Time Dial) setting. Repeat this step for all test levels
chosen. The curve portion extending to lower than 150% of
X
amps are inactive and can be
ignored. The tested points verify the operating times of the function.
b. The input voltage may be increased over the Voltage Control setting by at least 0.5 Volts, and
the function will drop out.
7.
Voltage Restraint Test:
Input Nominal Voltages and test as in step 6 above (same current input
values). Repeat step 6 above with reduced input voltage values and current reduced by an
equivalent percentage as the voltage reduction.
8.
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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