Schweitzer Engineering Laboratories SEL-321 - Loss-Of-Potential Supervision; Negative-Sequence Directional Element Test Using Single Voltage and Current Sources; Single-Pole Open Supervision

7-24 Maintenance and Testing Date Code 20011026
SEL-321/321-1 Instruction Manual
Loss-of-Potential Supervision
If ELOP = Y, Y1, or Y2, the relay supervises the directional logic using the Internal Loss-of-
Potential condition (ILOP). If ELOP = Y or Y2 the relay sets the 32QF element when a loss-of-
potential is detected, regardless of other signals applied to the relay. If you test the directional
logic using single voltage and current sources, set ELOP = N to simplify the test.
Single-Pole Open Supervision
The relay cannot issue an appropriate directional decision in single-pole trip applications if one
or more breaker poles is open when line-side voltage transformers are applied. The relay asserts
the 32QF element any time a Single-Pole Open condition is detected. To simplify directional
element tests, apply dc voltage to any inputs assigned to perform the 52 auxiliary functions, or
disable the Single-Pole Open logic by setting ESPO = N.
Negative-Sequence Directional Element Test Using Single Voltage and Current Sources
Step 1. Execute the SHOWSET command and verify the following relay settings: Z1MAG,
Z1ANG, Z2F, 50QF, Z2R, 50QR, and a2. The example relay settings use the
following settings: Z1MAG = 7.8 Ω, Z1ANG = 83.97°, Z2F = 0.77 Ω; 50QF = 0.5
amps secondary; Z2R = 5.45 Ω; 50QR = 0.5 amps secondary; a2 = 0.07.
Execute the SET command and change the example ELOP setting from Y to N.
Step 2. Select output contacts to indicate operation of the 32QF and 32QR elements. In this
example we use the OUT7 and OUT8 outputs.
From Access Level 2, execute the SET L n command to configure Output 7 and
Output 8 to close for assertion of the 32QF and 32QR elements, respectively.
=>>SET L 1 OUT7 <ENTER>
SET L 1 OUT7 <ENTER>SET L 1 OUT7 <ENTER>
SET L 1 OUT7 <ENTER>
SELogic group 1
OUT7 =NA
? 32QF
32QF32QF
32QF <ENTER>
<ENTER><ENTER>
<ENTER>
OUT8 =50PP2
? 32QR
32QR32QR
32QR <ENTER>
<ENTER><ENTER>
<ENTER>
OUT9 =NA
? END <ENTER>
END <ENTER>END <ENTER>
END <ENTER>
After you type END <ENTER> to end the set procedure, the relay displays the
current logic settings. At the prompt, type Y <ENTER> to accept those settings.
Connect outputs OUT7 and OUT8 to the sense input of your test set, an ohmmeter,
or some other contact sensing device.
Step 3. Connect the voltage source to the A-phase to neutral relay voltage input. Connect
the current source to the A-phase relay current input. Refer to the A-phase voltage
and current connections shown in Figure 7.6 as an example. The B-phase and C-
phase voltage connections are not required for this test.