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Step 5.
Apply AG reversed fault (i.e., I
by 105 degrees). The CARRY SEND contacts
should be "closed" and the CARRY STOP con-
tacts should be "open". (I
Zone 3 setting of 6 ohms.)
Step 6.
Change the LED mode to TEST and se-
lect the function "TK". Push the ENTER button;
the ENTER LED should be "ON" and the CARRY
SEND contacts should be closed.
Step 7.
In order to determine setting accuracy (6
ohms), the forward directional ground unit must
be disabled. Set FDGT = BLK. Repeat preceding
Step 4 of the Pilot Acceptance Test, with a trip in-
put current (I
) of 3 Amps (±5%).
a
Step 8.
Set the Forward Directional Ground Timer
(FDGT) from 0 to 15 cycles. Repeat Step 4 with
I
= 1.5 A. The relay should be tripped after the
a
delay time of FDGT.
NOTE: The FDOG trip is determined by the IOM
setting. It trips if 3I
ground directional unit picks up.
Step 9.
In order to perform the Breaker Failure
Reclose Block Test, change the setting of FDGT
= 0 and BFRB = NO. Repeat test Step 4; RB con-
tacts (TB3/1 and TB3/2) should not close.
Change BFRB to YES and repeat the test. The
RB contacts should be closed with a time delay
between 150 ms and 200 ms.
NOTE: For Va = Vb = Vc = 0, Ia = Ib = Ic = 0, the
setting of OSB = YES, WFEN = NO, and
the input of 52b = OV, the carrier SEND
contacts will be closed. This is not desir-
able, but occurs only on the test bench.
If tested with the relay system, V = 0 and
I = 0 mean that the 52b input is at a rated
voltage which will stop the SEND signal.
1.2.3
PUTT or POTT Schemes
Step 10. Change the setting to STYP = PUTT (for
underreach scheme) or STYP = POTT (for over-
reach scheme). In order to determine setting ac-
curacy (6 ohms), the forward directional ground
unit must be disabled. Set FDGT = BLK. Apply a
rated voltage to RCVR #1 terminals TB5/7(+) and
TB5/8(-), and apply an AG fault as shown in Step
10 of the Non-Pilot Acceptance Test. The trip
contact A should be closed at the input I
(5/92)
leads V
a
a
should be > 3A for the
a
>I
and the forward
0
om
= 3A
a
(± 5%); the target should show "PLTG AG", and
the CARRY SEND contact should be "closed" for
POTT setting. Do not test carry STOP for POTT
and PUTT schemes.
Step 11. Apply a reversed AG fault (I
105°). The relay should not trip, and the CARRY
SEND contact should stay "open".
Step 12. Remove the voltage on RCVR #1. Apply a
forward AG fault as shown in Step 10. The trip
contacts should remain "open" for I
Step 13. Change the LED mode to TEST and se-
lect the function "RS1". Push the ENTER button;
the ENTER LED should be "ON". Repeat Step 12
with the ENTER button depressed. The relay
should trip.
Step 14. Repeat steps 8 and 9 for FDGT and BFRB
tests, by using Step 10 with Ia = 1.5 A.
1.2.4
Weakfeed Scheme
Step 15. This function is for POTT only. In addition
to the setting changes in Step 2, change the fol-
lowing settings:
• STYP
POTT
• WFEN
YES
• Z3G
4.5
• Z3P
4.5
• Z3FR
REV
Apply a rated voltage to PLT/ENA terminals TB5/
9(+) and TB5/10(-), also RCVR #1 terminals TB5/
7(+) and TB5/8(-).
With V
= V
= V
an
bn
shown in Figure 6-1), the relay should operate
normally.
NOTE: Do not apply fault current.
Turn V
"OFF"; the relay should trip with a target
an
of WFT, and the Carrier Send contact (TB4-1 and
TB4-2) should close momentarily.
Reduce Van from 70 Vrms to 69Vrms and apply
a reverse AG fault current of 5A (i.e., I
by 105 degrees). Turn V
should not trip, and the Carrier Send contact
(TB4-1 and TB4-2) should stay open.
Step 16. This completes the basic Acceptance
Test for the MDAR Pilot System. (See subse-
I.L. 40-385.1B
leads V
a
a
= 5A.
a
= 70 Vrms applied (as
cn
leads V
a
"OFF"; the relay
an
by
an
6-9
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