Schweitzer Engineering Laboratories SEL-321 - Table 2.27: INST and TIME LED Qualifying Elements

2-42 Specifications Date Code 20011026
SEL-321/321-1 Instruction Manual
Targets Definition and Conditions for Illumination
INST Definition: Instantaneous tripping event. Illuminates if any element of
Table 2.27 is used in MTU and asserts for less time than the ITTD time delay setting
(Instantaneous Target Time) when TPA, TPB, TPC, or 3PT assert. The INST target
shall also illuminate if TPA, TPB, TPC, or 3PT assert and the other tripping targets
(TIME, COMM, or SOTF) do not illuminate.
TIME Definition: Time-delayed tripping event. Illuminates if any element of Table 2.27
is used in MTU and asserts for more time than ITTD when TPA, TPB, TPC, or 3PT
assert.
Table 2.27: INST and TIME LED Qualifying Elements
M1P - M4P
67N1 - 67N4
51PT
51QT
Z1G - Z4G
67Q1 - 67Q4
51NT
COMM Definition: Communications scheme assisted tripping event. Tripping is a result
of the communications-assisted trip logic.
SOTF Definition: Switch-onto-fault tripping event. SOTFE is asserted.
ZONE 1 Definition: Zone 1 or Level 1 element asserted. Illuminates if any of the
following elements are asserted: M1P, Z1G, 67N1, or 67Q1
ZONE 2 Definition: Zone 2 or Level 2 element asserted. Illuminates if any of the
following elements assert and like elements of shorter reach are not asserted: M2P,
Z2G, 67N2, or 67Q2.
ZONE 3 Definition: Zone 3 or Level 3 element asserted. Illuminates if any of the
following elements assert and like elements of shorter reach are not asserted: M3P,
Z3G, 67N3, or 67Q3.
ZONE 4 Definition: Zone 4 or Level 4 element asserted. Illuminates if any of the
following elements assert and like elements of shorter reach are not asserted: M4P,
Z4G, 67N4, or 67Q4.
EN Definition: Relay enabled (not latching).
A Definition: A-phase is involved. Illuminates if any of the following distance
elements are asserted:
• MAG1 - MAG4
• XAG1 - XAG4
• MAB1 - MAB4 if 21AB < 21BC and 21CA and │I
2
│ > │0.3⋅I
1
│
• M1P - M4P and │I
2
│ < │0.3⋅I
1
│