Schweitzer Engineering Laboratories SEL-321 - Page 298

7-28 Maintenance and Testing Date Code 20011026
SEL-321/321-1 Instruction Manual
=>>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. 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 three voltage sources and one current source to the relay as shown in
Figure 7.6.
Step 4. As described above, the relay 32Q element operates based upon the magnitude and
angle of negative-sequence voltages and currents. You can calculate the magnitude
and angle of V2 and I2, given the magnitude and angle of each of the phase
quantities using the equations below.
()
()
CB
2
A
3
1
2
CB
2
A
3
1
2
IaIaII
VaVaVV
⋅+⋅+⋅=
⋅+⋅+⋅=
Using a single-phase current source simplifies the I
2
calculation.
()
A
3
1
2
CB
I•I
amps0II
=
==
Assume that you apply the following test voltages:
°∠=
°−∠=
°∠=
120V0.67V
120V0.67V
0V0.49V
C
B
A
() volts12067•120112067•240100.49•V
3
1
2
°∠°∠+°−∠°∠+°∠=
()
volts1800.6V
volts120671206700.49•V
2
3
1
2
°∠=
°−∠+°∠+°∠=
Determine the test angle of A-phase current from the Z1ANG relay setting. For
Equation 7.2 to yield a positive result, I
A
, hence I
2
, should lag V
2
by the angle of
Z1ANG. For Equation 7.2 to yield a negative result, I
A
should lead V
2
by (180° -
∠Z1ANG°).