R.3.11
Date Code 20111215 Reference Manual SEL-421 Relay
SELOGIC Control Equation Programming
SELOGIC Control Equation Capacity
If the individual settings change causes a change in one or more SELOGIC
control equation settings SS1 through SS6, the active setting group can be
changed, subject to the newly enabled SS1 through SS6 settings.
SELOGIC Control Equation Capacity
SELOGIC control equation capacity is a measure of how much remaining
space you have available for programming. In both protection and automation,
SEL
OGIC control equation capacity includes execution capacity and settings
storage capacity.
The relay will reject any setting that exceeds the available settings storage
capacity and execution capacity. You can then accept the previous settings you
have entered and examine your settings.
Protection
The SEL-421 provides storage space for as many as 250 lines of protection
free-form programming. Because the relay executes protection fixed and free-
form logic at a deterministic interval, there is a limit to the amount of
SEL
OGIC control equation programming that the relay can execute. The relay
calculates total capacity in terms of settings capacity and execution capacity.
Rather than limit parameters to guarantee that your application not exceed the
maximum processing requirements, the relay measures and calculates the
available capacity when you enter SEL
OGIC control equations. The relay will
not allow you to enter programming that will cause the relay to be unable to
complete all protection SEL
OGIC control equations each protection processing
interval.
There are six protection settings groups that can be active. When a protection
settings group is active, the relay executes SEL
OGIC control equations in the
Global Settings, Protection Group Settings, Protection Free-Form Settings,
Output Settings, and several other settings areas. The relay calculates
protection capacities based on the total amount of SEL
OGIC control equation
programming executed when the protection settings group is active. Use the
STATUS S command to display the remaining settings capacity and execution
capacity for protection fixed and free-form logic.
Automation
The SEL-421 provides storage space for 10 blocks of as many as 100 lines of
automation free-form programming each. The relay executes automation
programming differently than protection logic programming. The result is that
automation free-form logic execution time varies with the amount of free-
form logic expressions that you enter. As you enter more expressions, the time
required for the relay to execute all expressions increases. You can display the
peak and average execution time using the STATUS S command.
There is a maximum execution capacity and settings storage capacity. If you
enter a setting that exceeds maximum capacity, the relay will reject the setting.
You will have the opportunity to reenter the setting or save any other settings
you entered during that session.
NOTE: The SEL-421-1 and the
SEL-421-2 have only one 100-line
automation programming block.
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