Schweitzer Engineering Laboratories SEL-321 - Page 67

Date Code 20011026 Specifications 2-43
SEL-321/321-1 Instruction Manual
B Definition: B-phase is involved. Illuminates if any of the following distance
elements are asserted:
• MBG1 - MBG4
• XBG1 - XBG4
• MBC1 - MBC4 if 21BC < 21AB and 21CA and │I
2
│ < │0.3⋅I
1
│
• M1P - M4P and │I
2
│ < │0.3⋅I
1
│
C Definition: C-phase is involved. Illuminates if any of the following distance
elements are asserted:
• MCG1 - MCG4
• XCG1 - XCG4
• MCA1 - MCA4 if 21CA < 21AB and 21BC and │I
2
│ < │0.3⋅I
1
│
• M1P - M4P and │I
2
│ < │0.3⋅I
1
│
G Definition: Ground is involved. Illuminates if any of the following elements are
asserted:
• Z1G - Z4G
• 67N1 - 67N4
Q Definition: Negative-sequence current detected. Illuminates if 51QP, or 50Q1 -
50Q4 are asserted.
51 Definition: Time-overcurrent element timed out. Illuminates if 51PT, 51QT, or
51NT are asserted.
50 Definition: Level 1 - 4, high-set, or Stub Logic overcurrent elements are
asserted. Illuminates if any of the following elements listed are asserted:
• 67N1 * ZONE 1 LED conditions satisfied
• 67N2 * ZONE 2 LED conditions satisfied
• 67N3 * ZONE 3 LED conditions satisfied
• 67N4 * ZONE 4 LED conditions satisfied
• 67Q1 * ZONE 1 LED conditions satisfied
• 67Q2 * ZONE 2 LED conditions satisfied
• 67Q3 * ZONE 3 LED conditions satisfied
• 67Q4 * ZONE 4 LED conditions satisfied
• 50H
• 50HH
• 50MF