Schweitzer Engineering Laboratories SEL-411L - Multiterminal Test Procedures; Pickup Setting Check (Multiterminal); Radius Setting Check (Multiterminal)

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Date Code 20150401 SEL Application Guide 2015-12
Step 7. Assuming that the angles are measured as 0 to +180 degrees and 0 to –180 degrees,
respectively, check that the block angle is set within ±5 percent of the angle
determined by (3):
87LkA ANG1 ANG2= +
(3)
where:
87LkA is 87LPA for an 87LA, 87LB, or 87LC test; 87LQA for an 87LQ test;
and 87LGA for an 87LG test.
Repeat the preceding steps for each of the differential elements.
Note: You can also test the extended security differential settings of the relay by choosing the
87TESTS = S option in test mode, which switches the normal radius and angle settings
to secure mode settings.
MULTITERMINAL TESTS
Pickup Setting Check
Step 1. Connect the proper local current source. Do not apply current at any remote
terminal. Start with no current applied.
Step 2. Slowly increase the applied local current until Relay Word bit 87TOUT asserts.
The pickup value should be within ±5 percent of the value calculated by (4):
PICKUP
I 87LTAPn •87LkP
=
(4)
where:
87LTAPn is 87LTAPW or 87LTAPX, depending on which input is under test.
87LkP is 87LPP for an 87LA, 87LB, or 87LC test; 87LQP for an 87LQ test;
and 87LGP for an 87LG test.
Radius Setting Check
Step 1. Connect the proper local and remote current sources.
Step 2. Set the magnitude of the local current greater than the pickup value calculated
in (4). Set the local current angle at 0 degrees.
Step 3. Set the magnitude of the remote current, as determined by (5), at 180 degrees.
REMOTE
REMOTE
LOCAL
87LTAPn
I [magnitude of the local current]•
87LTAPn
=
(5)
where:
87LTAPn is 87LTAPW or 87LTAPX, depending on which input is under test.
Step 4. Confirm that 87TOUT is deasserted.