Schweitzer Engineering Laboratories SEL-321 - Enabling Distance Zones; Element Label Comment; Setting the Direction of Zones and Overcurrent Elements; Phase Mho Distance Characteristics

2-2 Specifications Date Code 20011026
SEL-321/321-1 Instruction Manual
Other terminal information includes:
• Fault location option (Y = Two-terminal, R = Radial, N = Disable)
• Line length (LL)
• Current and potential transformer ratios (for presenting metering and event report data in
primary values).
ENABLING DISTANCE ZONES
Zero to four zones of phase mho, ground mho, and ground quadrilateral protection can be
individually selected. Use the PMHOZ, GMHOZ, and QUADZ settings to specify how many
zones of each type of distance element you need.
Element Label Comment
Elements with zone labels are associated with distance elements. Elements with level labels are
associated with negative-sequence and residual overcurrent elements.
SETTING THE DIRECTION OF ZONES AND OVERCURRENT ELEMENTS
The DIR1 - DIR4 settings establish the direction of characteristics associated with Zones and
Levels 1 - 4. Table 2.2 shows which elements are affected by DIR1 - DIR4.
Table 2.2: Zone and Level Elements Affected by DIR1 - DIR4
Affected Characteristics
Setting
(F/R) Phase Mho
Ground Mho
and Quad I
R
>> 3I
2
>>
DIR1
DIR2
DIR3
DIR4
M1P
M2P
M3P
M4P
Z1G
Z2G
Z3G
Z4G
67N1
67N2
67N3
67N4
67Q1
67Q2
67Q3
67Q4
(F = Forward, R = Reverse)
PHASE MHO DISTANCE CHARACTERISTICS
Each phase mho zone has independent phase-to-phase overcurrent supervision. All instantaneous
and time delayed outputs can be used in the programmable logic to create control, alarm, and
indication schemes.