Rockwell Automation 865 Differential Protection Relay - Manual (Page 4)

ii Table of Contents
865-UM001A-EN-P – July 2009
Retardation Time .............................................................. 3-3
Reset Time (Release Time) .............................................. 3-4
Hysteresis or Dead Band .................................................. 3-5
Differential Overcurrent Protection ΔI> (87) ......................... 3-6
Parameters of the Differential Overcurrent Stages ......... 3-10
Overcurrent Protection I> (50/51) ........................................ 3-11
Two Independent Stages ................................................ 3-11
Inverse Operation Time .................................................. 3-11
Inverse Time Limitation ................................................. 3-11
Setting Groups ................................................................ 3-11
Recorded Values of the Latest Eight Faults ................... 3-14
Current Unbalance Protection I 2 >, I’ 2 (46) ........................... 3-15
Inverse Delay ................................................................. 3-15
More Stages (Definite Time Delay only) ....................... 3-15
Setting Groups ................................................................ 3-15
Recorded Values of the Latest Eight Faults ................... 3-17
Earth Fault Protection I
0
> (50N/51N) ................................... 3-17
Input Signal Selection .................................................... 3-18
Intermittent Earth Fault Detection .................................. 3-18
Four Independent Undirectional Earth Fault
Overcurrent Stages ................................................... 3-18
Inverse Operation Time (I 0 > stage only) ........................ 3-19
Inverse Time Limitation ................................................. 3-19
Setting Groups ................................................................ 3-19
Recorded Values of the Latest Eight Faults ................... 3-22
Thermal Overload Protection T> (49) .................................. 3-22
Thermal Model ............................................................... 3-22
Time Constant for Cooling Situation ............................. 3-23
Heat Capacitance, Service Factor and Ambient Temp. ...3-23
Example of a Behavior of the Thermal Model ............... 3-24
Initial Temperature Rise after Restart ............................ 3-24
Alarm Function .............................................................. 3-24
Circuit-Breaker Failure Protection CBFP (50BF) ................ 3-26
Recorded Values of the Latest Eight Faults .......................... 3-27
Arc Fault Protection (50ARC/50NARC) - Optional ............ 3-28
Three Stages for Arc Faults ............................................ 3-28
Light Channel Selection ................................................. 3-28
Binary Input ................................................................... 3-28
Binary Output ................................................................. 3-29
Delayed Light Indication Signal .................................... 3-29
Pick Up Scaling .............................................................. 3-29
Recorded Values of the Latest Eight Faults ................... 3-30
Programmable Stages (99) .................................................... 3-31
Available Signals to be Supervised by the
Programmable Stages .............................................. 3-31
Eight Independent Stages ............................................... 3-31
Setting Groups ................................................................ 3-31
Recorded Values of the Latest Eight Faults ................... 3-32
Chapter 3
Protection Functions
(cont.)