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I.L. 40-385.1B
478
+
----------------------------- -
(T
) =
4.1/0.5 -1.27
MSEC
T
=
1073 msec
MSEC
1.073 sec ± 5 % to trip
=
For values of 3I
between 1.0 and 1.5, the following
0
equation would apply:
(
)
9200
×
---------------- -
(T
) =
MSEC
3I
–
1
0
The following equation can be used to calculate the
trip time for all CO curves from CO-2 to CO-11:
T(sec) =
K
GTC
×
T
+
-------------------------- -
----------------- -
0
(
)
p
24 000
3I
–
C
0
R
GTC
×
T(sec) =
--------------------- -
----------------- -
(
)
,
3I
–
1
24 000
0
3I
OF
where
3I
=
---------------- -
0
GBPU
GBPU = Pickup current setting (0.5 to 4.0A).
GTC = Time curve dial setting (1 to 63).
T
, K, C, P and R are constants, and are shown in
o
Table 6-2.
Step 24. For a Zero Sequence Directional unit (DI-
RU = ZSEQ), the tripping direction of MDAR is:
the angle of 3I
leads 3V
0
+210°. Change the setting of GDIR to "YES". Ap-
ply AG fault as shown in preceding Step 10, Fig-
ure 6-1. The relay should trip at the following
angles:
• +28°
• -60° (± 88°)
• -148°
The relay should not trip at the angles of:
• +32°
• +120° (± 88°)
• -152°
For a Negative Sequence Directional Unit (DIRU =
NSEQ), the tripping direction of MDAR is: I
6-6
4122
24
----- -
24
GTC
(
)
----------- -
CO 8 only
–
24
(
≥
)
for 3I
1.5
,
0
(
<
<
)
for 1 3I
1.5
0
between +30° and
0
leads V
2
by a value between +8° and +188°. The relay should
trip at the following angles:
• +3°
• -82° (± 85°)
• -167°
The relay should not trip at the angles of:
• +13°
• +98° (± 85°)
• +183°
Step 25. For a dual polarizing ground directional
unit (DIRU = DUAL) test, connect the test circuit
shown in Figure 6-4; apply lp 1.0A
minals 12 (+) and 11(-), and apply a balanced 3-
phase voltage (70V) to Va, Vb, Vc, and Vn. Apply
Ia = 4A to terminals 6(+) and 5(-).
NOTE: In order to eliminate the voltage polariz-
ing effect, make sure the voltages are
finely balanced so that 3V0 is less than
1.0 volt.
The relay should trip at the following angles:
• -3°
• -90 o ( ± 87 ° )
• -177°
The relay should not trip at the following angles:
• +3°
• +90° ( ±87°)
• +177°
1.1.10 CIF, STUB, Iom, IL and LV Tests
Step 26. Set the relay per Table 6-1. Change the
following settings: Iom = 3, IL = 2, CIF = CIFT,
and connect a rated dc voltage to 52b, between
TB5/3 (+) and TB5/4 (-). Apply an AG fault as
shown in Step 10 (Figure 6-1). The relay should
trip at I
= 2A (IL) with CIF target. Change IL set-
a
ting from 2 to 3.5A and repeat the test shown in
Step 26. The relay should trip at I
CIF target.
Step 27. LV setting test. Set LV = 60 and with I
4A, apply AG fault as shown in Step 10. The CIF
trip should be for V
Step 28. For STUB Bus Protection (SBP), check
the blue jumpers on the Interconnect module.
2
∠
to ter-
–
90°
= 3A (I
a
om
<60 Vrms ± 5%.
AN
) with
=
AN
(5/92)
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