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M-3410A Instruction Book
5–18
46 Negative Sequence Overcurrent Inverse Time (Current Unbalance) –
Generator Protection (Curve I
2
2
t = K, or Curve D-9)
VOLTAGE INPUTS
:
None
CURRENT INPUTS
:
Configuration C1
TEST SETTINGS
:
Pickup
P
%
(3 to 100)*
(*
of Nominal Current)
Time Dial Setting
K
(1 to 95)
(Negative Sequence Overcurrent Inverse Time Curve 9)
Definite Maximum
D
cycles
(600 to 65,500)
Programmed Outputs
Z
OUT
(1 or 2)
Function 46 Definite Time
Disable
Functions 27, 79
Disable
1.
Disable functions as shown. See Section 3.2, Setpoints and Time Settings, for procedure.
2.
Confirm settings to be tested.
3.
Connect inputs in Configuration C1 designated above. The phase angles of currents should be set
as
I
A
=
s
0°,
I
B
=
s
120°,
I
C
=
s
–120°.
4.
The current pickup level at a percentage setting is: Pickup current = (
P
% ÷ 100) x
Nominal
Current
(see Table A-3, System Setup Record Form).
5.
Test levels may be chosen at any percentages of Nominal Current which are a minimum of 5%
higher than the pickup percentage,
P%
. (Suggest 4 or 5 test levels chosen and calculated in
amps.)
6.
Time Test
: With output contacts (
Z
) connected to stop the timer, apply currents equal to the
chosen test levels calculated in step 5 and start timing. The operating time will be as read from
Figure D-9,
I
2
2
t = K, Negative Sequence Inverse Time Curves, negative sequence current in % of
Nominal Current and appropriate
K
(Time Dial) setting,
or the maximum trip time (whichever is
faster)
&
3 cycles or
&
10%. Repeat this step for all test levels chosen.
7.
Reset Time Test
: If it is desired to test the reset time, begin timing immediately when the input
current is reduced below the pickup value. Holding the
TARGET/OUTPUT RESET
pushbutton in,
stop timing when the
CUR UNBALANCE 46
LED extinguishes. The time should be approximately
4 minutes.
8.
If testing is complete, enable any functions disabled for this test. If other tests are to be
completed, check the proper functions to disable for the next test and proceed from this point.
Q
Q
Q
Q
Q
NOTE
: If retesting is required, the unit should be powered down or wait 4 minutes before the next test to
assure resetting of the timer. (For proper testing, use I
≤
3 x CT rating)
Summary of Contents for Syncrocloser M-3410A
Page 1: ...Instruction Book M 3410A Intertie Generator Protection Relay ...
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Page 161: ...1 3 A B C M 3410A Instruction Book 4 40 This Page Left Intentionally Blank ...
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