Rockwell Automation 865 Differential Protection Relay - Manual (Page 75)

Protection Functions 3-31
865-UM001A-EN-P – July 2009
Programmable Stages (99)
For special applications the user can built his own protection stages
by selecting the supervised signal and the comparison mode.
The following parameters are available:
Priority •
If operation times less than 60 milliseconds are needed
select 10 ms. For operation times under one second 20 ms
is recommended. For longer operation times and THD
signals 100 ms is recommended.
Link
•
The name of the supervised signal (see table below).
Cmp
•
Compare mode. ‘>’ for over or ‘<’ for under comparison.
Pick-up
•
Limit of the stage. The available setting range and the unit
depend on the selected signal.
t
•
Definite time operation delay
Hyster •
Dead band (hysteresis)
NoCmp
•
Only used with compare mode under (‘<’). This is the limit to
start the comparison. Signal values under NoCmp are not
regarded as fault.
Available Signals to be Supervised by the Programmable Stages
Alarm stages link signals Task interval
IL1 – IL3, IL1W-IL3W, I’L1W-I’L3W, IL, I’L 100ms
Io, Io2, Iocalc, I’oCalc, I1, I2, I2/I1, I2/In, I’1,
I’2, I’2/I’1, I’2/In, dIL1, dIL2, dIL3
THDIL1, THDIL2, THDIL3
Eight Independent Stages
The relay has eight independent programmable stages. Each
programmable stage can be enabled or disabled to fit the intended
application.
Setting Groups
There are two settings groups available. Switching between setting
groups can be controlled by digital inputs, virtual inputs (mimic
display, communication, logic) and manually.
There are two identical stages available with independent setting
parameters.