ERL L-PRO 4000, Руководство пользователя

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7 Acceptance/Protection Function Test Guide
7-42 L-PRO 4000 User Manual D02706R02.30
3. Inject fault.
Observe Relay Target: “46-51 Trip”
End of 46-51 test.
Directional
Element
Positive
Sequence
Current
Supervision
Threshold
(50ILpos) Test
(see OR 265, for details see Figure 7.27: Directional Element Logic on page 7-
38)
Settings
• Directional
• 50ILpos (Positive Sequence (I1) Low Set = 0.2 A fixed)
• 46-50 Pickup = 5.0 A
Figure 7.29: Negative Sequence Instantaneous and Time OverCurrent Logic (46-50/
46-51)
Test Calculations
The relay directional element has a fixed positive sequence current setting of
4% of I
nominal
that is used to supervise the directional control. If the positive
sequence current falls below 4% of I
nominal
, the directional control becomes
non-directional. So, for directional control of the 46 element, the following is
required:
Negative Sequence Current (I
2
) greater than pickup AND Positive Se-
quence Current (I
1
) greater than or equal to 0.2 A (4% I
nominal
).
For this test inject a Reverse Negative Sequence fault:
With the I
1
Directional Supervision threshold not exceeded, the directional
unit is disabled, therefore the directional element will be non-directional.
This means that the 46 element is able to operate in the reverse direction as
well as in the forward direction.
When the I
1
Directional Supervision is exceeded, the 46 drops out as it has
now become Directional (forward) only.
Testing is accomplished by applying 3-phase balanced I
2
quantities sufficient
to pickup the 46 element and then increasing the magnitude of any single-
phase.
0
50 I2
288
51 I1
If Directional or combined, T must be greater than
5ms
T
0
289
46-50 Directional Control
46-51 Directional Control
Timer is active, only if it's directional or com
Out 8
Alarm
Out 9