Sel 551 - Table 8.1 Instantaneous Overcurrent Elements and Corresponding Settings;Relay Word Bits;Tar Commands

8.10
SEL-551 Relay Instruction Manual Date Code 20110408
Testing and Troubleshooting
Acceptance Testing
Step 3. Purpose:
Connect and apply a single current test source until the
appropriate LED illuminates.
Method:
a. Connect a single current test source (i.e., source 1 to
current input IA) as shown in Figure 8.3.
b. Turn on the current test source for the phase under test,
and slowly increase the magnitude of current applied
until the appropriate element asserts (i.e., 50P1),
causing the LED to illuminate (i.e., fifth from the left;
see Table 5.5).
c. Note the magnitude of the current applied. It should
equal the 50P1P setting ±5 percent of the setting and
±0.1 A secondary.
Step 4. Purpose:
Repeat test for each instantaneous overcurrent element.
Method:
a. Repeat Step 1–Step 3 for each instantaneous
overcurrent element listed in Tabl e 8.1 .
b. Remember to view the element with the TAR command
(see Table 5.6). The computer terminal will display the
LED labels from left to right when the TAR command
is issued.
Table 8.1 Instantaneous Overcurrent Elements and Corresponding Settings/
Relay Word Bits/TAR Commands
Element Pickup Setting Relay Word Bit TAR
Phase Level 1 50P1P 50P1 2
Phase Level 2 50P2P 50P2 2
Phase Level 3 50P3P 50P3 2
Phase Level 4 50P4P 50P4 2
Phase Level 5 50P5P 50P5 3
Phase Level 6 50P6P 50P6 3
Independent A-Phase 50ABCP 50A 4
Independent B-Phase 50B
Independent C-Phase 50C
Neutral Ground Level 1 50N1P 50N1 3
Neutral Ground Level 2 50N2P 50N2 3
Residual Ground Level 1 50G1P 50G1 3
Residual Ground Level 2 50G2P 50G2 3
Negative-Sequence Level 1 50Q1P 50Q1 3
Negative-Sequence Level 2 50Q2P 50Q2 3