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6.2 MEASURING UNIT TESTS
1. Protection Settings:
OVERCURRNT
(601)
50 = YES
(605)
50G = YES
(610)
51G = YES
(611)
51G_DIRCNL = NO
(612)
51GPICKUP = [________] Amps
(614)
51GCURVE = [________] Curve
(615)
51GTIMDIAL = [________] Time dial
(617)
51G_RESET = FAST
The 51G function is calculated with the equation:
51G = 3 I
0
where I
is equal to the zero-sequence current. Since I
0
I
op
I
=
------ -
(eq. 6–5)
0
3
Substituting Equation 6–5 into Equation 6–4 yields:
I
= 51G
op
Therefore, 51G will pick up when I
the time-dial curves shown in Section 2.4: INVERSE CURVES on page 2–29.
6
CAUTION: If the test current exceeds 2 I
should be applied with a 50% duty cycle. For instance, if the current is applied for 5
minutes, it should be left off for 5 minutes before it is reapplied.
2. Connect the relay as shown in Figure 4–3: PHASE TO GROUND TEST CONNECTIONS on page 4–16.
NOTE: Start the timer when I
3. For this test remove the relay from test mode and assign TOCTRP to A1.
(2007) A1 = index 119; TOCTRP
4. Apply I
at 2 x 51PICKUP = [________] A rms and start the timer. Leave the current on until the A1 con-
op
tact close then stop the timer. The time should be within ±7% of the value found in the time current charac-
teristic in use.
5. Reduce I
to zero.
op
6. Repeat steps 4. and 5. for I
rms. Verify that the times are within ±7% of the value found in the time current characteristic in use.
This test has fixed settings that are not user selectable. See Section 5.1.10: T9 – UNDERVOLTAGE TEST on
page 5–8 for testing with factory settings.
6-
6
(eq. 6–4)
≥ 51GPICKUP. The time it takes for 51G to pick up is determined by
op
is applied, and stop the timer when A1 closes (the relay trips).
op
at 6 x 51PICKUP = [________] A rms and 10 x 51PICKUP = [________] A
op
LPS-O Line Protection System
6 FUNCTIONAL TESTS (USER SETTINGS)
6.2.8 T8 – GROUND TIME OVERCURRENT TEST
is single phase, I
op
(where I
is the rated current), then the current test
n
n
6.2.9 T9 – UNDERVOLTAGE TEST
is given by
0
GE Power Management
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