5-274
F35 MULTIPLE FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CONTROL ELEMENTS
CHAPTER 5: SETTINGS
5
5.8.7 Digital elements
SETTINGS
CONTROL ELEMENTS
DIGITAL ELEMENTS
DIGITAL ELEMENT 1(48)
There are 48 identical digital elements available, numbered 1 to 48. A digital element can monitor any FlexLogic operand
and present a target message and/or enable events recording depending on the output operand state. The digital element
settings include a name to be referenced in any target message, a blocking input from any selected FlexLogic operand,
and a timer for pickup and reset delays for the output operand.
DIGITAL ELEMENT 1 INPUT
— Selects a FlexLogic operand to be monitored by the digital element.
DIGITAL ELEMENT 1 PICKUP DELAY
— Sets the required time delay from element pickup to element operation. If a pickup delay
is not required, set to "0," To avoid nuisance alarms, set the delay greater than the operating time of the breaker.
DIGITAL ELEMENT 1 RESET DELAY
— Sets the time delay to reset. If a reset delay is not required, set to “0.”
DIGITAL ELEMENT 1 PICKUP LED
— This setting enables or disabled the digital element pickup LED. When set to “Disabled,” the
operation of the pickup LED is blocked.
DIGITAL ELEMENT 1
DIGITAL ELEMENT 1
FUNCTION: Disabled
Range: Disabled, Enabled
DIG ELEM 1 NAME:
Dig Element 1
Range: up to 16 alphanumeric characters
DIG ELEM 1 INPUT:
Off
Range: FlexLogic operand
DIG ELEM 1 PICKUP
DELAY: 0.000
s
Range: 0.000 to 999999.999 s in steps of 0.001
DIG ELEM 1 RESET
DELAY: 0.000
s
Range: 0.000 to 999999.999 s in steps of 0.001
DIGITAL ELEMENT 1
PICKUP LED: Enabled
Range: Disabled, Enabled
DIG ELEM 1 BLOCK:
Off
Range: FlexLogic operand
DIGITAL ELEMENT 1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
DIGITAL ELEMENT 1
EVENTS: Disabled
Range: Disabled, Enabled
Digital elements run once per power system cycle.
As such they can easily fail to react to an input signal or a block signal with a duration less than one power system
cycle. This also means that digital element output can react up to one power system cycle later than the pickup
and reset delay settings indicate.
Do not use digital elements with transient signals, such as communications commands. Do not use digital
elements where random delays of up to one cycle cannot be tolerated, such as in high speed protection.