P.14.20
SEL-411L Relay Protection Manual Date Code 20151029
SELOGIC Control Equation Programming
SEL
OGIC Control Equation Elements
In protection free-form programming, the relay evaluates the timer at
execution of the timer Input SEL
OGIC control equation (PCTnnIN). The relay
loads the Pickup Time (PCTnnPU) and Dropout Time (PCTnnDO) into the
timer when the relay observes the appropriate edge in the input. If you enter a
math expression for Pickup Time or Dropout Time, the relay uses the value
calculated before the Input SEL
OGIC control equation. If your Pickup Time or
Dropout Time equation is below the Input equation (has a higher expression
line number), the relay will use the value calculated on the previous SEL
OGIC
control equation execution interval. Because the relay calculates the last value
for pickup or dropout in this manner, we recommend for most applications
that you enter the Pickup Time, Dropout Time, and Input statements together
in the order shown in Example 14.7. You can view the status of the protection
conditioning timer output Relay Word bits using the TAR PCTnnQ
command, where nn is the number of the protection conditioning timer. You
can also view the status of these timer elements through the relay front-panel
LCD display by selecting
RELAY ELEMENTS from the Main Menu and scrolling
through the rows of Relay Word bits.
Sequencing Timers
Sequencing timers are useful for sequencing operation. There are two main
differences between sequencing timers and conditioning timers. First,
sequencing timers integrate pulses of the input to count up a total time.
Second, the elapsed time a sequencing timer counts is visible; you can use this
time in other SEL
OGIC control equation programming or make this time
visible through one of the relay communications protocol interfaces.
Sequencing timers are available in the protection free-form area and
automation free-form area as shown in Table 14.15. Sequencing timers have
three input parameters and two outputs listed in Table 14.16.
A sequencing timer counts time by incrementing the Elapsed Time when
SEL
OGIC control equation execution reaches the Input equation if the Reset is
off and the Input is on. The Output turns on when the Elapsed Time reaches or
Table 14.15 Sequencing Timer Quantities
Type Quantity Name Range
Protection free-form sequencing timers 32 PST01–PST32
Automation free-form sequencing timers 32 AST01–AST32
Table 14.16 Sequencing Timer Parameters
Type Item Description Setting
Name
Examples
Input Input Value that the
relay times
Boolean SELOGIC control
equation setting
PST01IN
AST07IN
Input Preset Time Time the input
must be on before
the output turns on
Time value. Protection uses
cycles, while automation
uses seconds.
PST01PT
AST07PT
Input Reset Timer reset Boolean SEL
OGIC control
equation setting
PST01R
AST07R
Output Elapsed Time Time accumulated
since the last reset
Value for math SEL
OGIC
control equations. Protec-
tion uses cycles, while
automation uses seconds.
PST01ET
AST07ET
Output Output Timer output Value for Boolean
SEL
OGIC control equations
PST01Q
AST07Q
To Next Page
Loading...
