Schweitzer Engineering Laboratories SEL-701 - SEL OGIC Control Equations

Date Code 20010719 701 Motor Protection Relay
SELOGIC
®
Control Equations & Relay Logic
SEL
OGIC Control Equations
B.9
SELOGIC Control Equations
SELOGIC control equations combine relay protection and control elements with
logic operators to create custom protection and control schemes. This section shows
how to set the protection and control elements (Relay Word bits) in the SEL
OGIC
control equations.
SEL
OGIC control equations are set with combinations of Relay Word bits to
accomplish such functions as:
 Tripping circuit breakers.
 Assigning contact inputs to functions.
 Operating contact outputs.
You can use SEL
OGIC control equations to create traditional or advanced custom
schemes.
SELOGIC Control Equation Operators
Build SELOGIC control equation settings using logic similar to Boolean algebra
logic, by combining Relay Word bits together using one or more of the six SEL
OGIC
control equation operators listed in Table B.3. These operators are processed in a
SEL
OGIC control equation in the order shown in Table B. 3.
Table B.3 SEL OGIC Cont rol Equation O perators
SELOGIC Control Equation AND Operator [*]
Use the asterisk [*] symbol to denote logical AND operations. When you use the
[*] between two Relay Word bits, both must pick up in order for the relay to perform
the operation in question. For instance, if SV1 is the equation that controls SEL
OGIC
control equation variable 1, you could set SV1 equal to:
Equation B.1
Table B.3 SELOGIC Control Equation Operators (listed in processing order)
Operator Logic Function
/ Rising edge detect
\ Falling edge detect
( ) parentheses
! NOT
* AND
+ OR
SV1 50P1T * IN4=