Schweitzer Engineering Laboratories SEL-421-4, Instruction Manual

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13.23
Date Code 20171006 Instruction Manual SEL-400 Series Relays
SEL
OGIC
Control Equation Programming
SEL
OGIC
Control Equation Elements
Protection Counter 1 counts close operations of the circuit breaker associ-
ated with the 52AA1 element. Initially, the current value, PCN01CV, is zero.
The relay increments the current value each time the circuit breaker closes.
The relay increases the count value, PCN01CV, each time the circuit breaker
closes and the element 52AA1 value changes from 0 to 1 (a rising edge).
When the count reaches 1000, the timer automatically resets and begins
counting again.
# Example protection counter programming
#
# This example counts how many times a circuit breaker closes
# The counter automatically resets every 1,000 operations
PCN01PV := 1000
PCN01R := PCN01Q
PCN01IN := 52AA1
The SEL
OGIC
control equations below provide multiple-change detection
counting both close and open operations of the circuit breaker. The interme-
diate value PSV01 turns on for one processing interval each time the circuit
breaker closes. The intermediate value PSV02 turns on for one processing
interval each time the circuit breaker opens. The OR combination of PSV01
and PSV02 contains a rising edge for each circuit breaker operation, open or
closed, that Protection Counter 1 counts.
# Example protection counter programming
#
# This example counts how many times a circuit breaker operates either
open or closed
#
# Detect OPEN and CLOSE and combine
PSV01 := R_TRIG 52AA1 # Pulse for each close
PSV02 := F_TRIG 52AA1 # Pulse for each open
PSV03 := PSV01 OR PSV02 # Pulse for each open or close
#
# The counter automatically resets every 1,000 operations
PCN01PV := 1000
PCN01R := PCN01Q
PCN01IN := PSV03 # Count open and close operations
PSV04 := PCN01CV >900 # PSV04 signals impending reset
Example 13.9 Counter Programming (Continued)