Schweitzer Engineering SEL-351P, Quick Start Manual

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G-4 Setting SEL
OGIC
®
Control Equations Date Code 990430
SEL-351P Manual Técnico
Operators in a SEL
OGIC
Control Equation setting are processed in the order shown in
Table APPENDIX G: .1.
SEL
OGIC
Control Equation Parentheses Operator ( )
More than one set of parentheses ( ) can be used in a SEL
OGIC
Control Equation setting. For
example, the following SEL
OGIC
Control Equation setting has two sets of parentheses:
SV7 = (SV7+IN101)*(50P1+50N1)
In the above example, the logic within the parentheses is processed first and then the two
parentheses resultants are ANDed together. The above example is from Figure 7.25 in
Section 7:
Inputs, Outputs, Timers, and Other Control Logic
. Parentheses cannot be “nested”
(parentheses within parentheses) in a SEL
OGIC
Control Equation setting.
SEL
OGIC
Control Equation NOT Operator !
The NOT operator ! is applied to a single Relay Word bit and also to multiple elements (within
parentheses). Following are examples of both.
Example of NOT Operator ! Applied to Single Element
The internal circuit breaker status logic in the
SEL-
351P operates on 52a circuit breaker auxiliary
contact logic. The SEL
OGIC
Control Equation circuit breaker status setting is labeled 52A. See
Optoisolated Inputs in Section 7: Inputs, Outputs, Timers, and Other Control Logic and Close
Logic in Section 6: Close and Reclose Logic for more information on SEL
OGIC
Control
Equation circuit breaker status setting 52A.
When a circuit breaker is closed, the 52a circuit breaker auxiliary contact is closed. When a
circuit breaker is open, the 52a contact is open.
The opposite is true for a 52b circuit breaker auxiliary contact. When a circuit breaker is closed,
the 52b circuit breaker auxiliary contact is open. When the circuit breaker is open, the 52b
contact is closed.
If a 52a contact is connected to optoisolated input IN101, the SEL
OGIC
Control Equation circuit
breaker status setting 52A is set:
52A = IN101
Conversely, if a 52b contact is connected to optoisolated input IN1, the SEL
OGIC
Control
Equation circuit breaker status setting 52A is set:
52A = !IN101 [=NOT(IN101)]
With a 52b contact connected, if the circuit breaker is closed, the 52b contact is open and input
IN1 is deenergized [IN1 = 0 (logical 0)]:
52A = !IN101 = NOT(IN101) = NOT(0) = 1
Thus, the SEL
OGIC
Control Equation circuit breaker status setting 52A sees a closed circuit
breaker.