# 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
ZLF 0 0 0 0 0 0 0

Distance Protection

Final Order Code
ZLF 0 0 0 0 0 0 0
  • DI
  • DO
  • AI (-5 - +20mA)
  • AI (0-300vDC)
  • CT
  • PT
  • Communication Protocol
  • Serial Ports
  • Ethernet Ports
ANSI Functions
87PH Phase Differential unit with Restraint
87PH/50 Phase Differential unit without Restraint
87N Neutral Differential unit with Restraint
87POS Positive Sequence Differential unit with Restraint
87NEG Negative Sequence Differential unit with Restraint
87/50FD Fault Detector
27FD Fault Detector in Weak Infeed conditions
87P External Fault Detector
64REF Restricted Earth Faults
50OF Close-onto-Fault Detector
50 Phase Instantaneous Overcurrent
51 Phase Time-delayed Overcurrent
50N Neutral Instantaneous Overcurrent (calculated IN)
51N Neutral Time-delayed Overcurrent (calculated IN)
50Q Negative Sequence Instantaneous Overcurrent
51Q Negative Sequence Time-delayed Overcurrent
50G Ground Instantaneous Overcurrent
51G Ground Time-delayed Overcurrent (measured IG)
50STUB STUB Bus Protection
50V Voltage Dependent Instantaneous Overcurrent
51V Voltage Dependent Time-delayed Overcurrent
67 Phase Directional
67N Neutral Directional
67G Ground Directional
67P Positive-Sequence Directional
67Q Negative Sequence Directional
Harmonics Blocking
49W Line Thermal Image
49G Neutral Thermal Image
26 Hot Spot Thermal Image
50OL Overload Instantaneous unit
51OL Overload Time-delayed unit
27 Phase Undervoltage/td>
59 Phase Overvoltage
59N Neutral Overvoltage
47 Negative Sequence Overvoltage
64 Ground Overvoltage
81M Overfrequency
81m Underfrequency
81D Rate of Change of the Frequency
Load Shedding
59V/Hz Overexcitation
25 Synchrocheck
50BF Breaker Failure
Cold Load
21N Ground Distance Zones
21P Phase Distance Zones
50SUP Phase Overcurrent for Distance Supervision
Load Encroachment
85-21 Teleprotection Schemes for Distance Units
85-67 Teleprotection Schemes for Overcurrent Units
Open Phase Detector
Remote Open Breaker Detector
60FF Fuse Failure Detector
60VT VT Supervision
68/78 Power Swing Detector
60CT CT Supervision
3 Coil Supervision
Breaker Supervision
Phase Selector
Open Pole Detector
2 Pole Discordancy
Dead-Line Detector
Saturation Detector
79 Recloser
Trip logic and Command
Fault Locator
Multi Far-end Fault locator
Lian Electric