CHAPTER 4: SETPOINTS CONTROL
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 4–349
PB “Bypass” (Hardcoded SLD Pushbutton)
Blocking of the command can be bypassed using the SLD pushbutton “Bypass” (see Figure
4-153:SLD Pushbutton “Bypass Block” logic diagram). When pressed, the previously
applied block is bypassed (see figures: Local Control for breakers/Local Control for
contactor). For example if the block was applied when the Breaker/Switch was opened,
pressing the PB “Bypass” will allow closing command. If the bypass is active for the
selected breaker (contactor) or switch, a letter “By” appears next to the symbol in the SLD.
Figure 4-153: SLD Pushbutton “Bypass Block” logic diagram
PB “Tag” (hardcoded SLD pushbutton)
Lockout/Tagout is a practice and procedure to safeguard employees from unexpected
energization or startup of machinery and equipment, or hazardous energy during service
or maintenance activities. If a breaker (contactor) or disconnect switch is tagged, the open
and close controls are inhibited.
Both remote and local control commands are blocked if the tagged operand BKR# Tag ON,
or SW# Tag ON is active for the selected particular breaker (contactor) or switch
respectively. The breaker (contactor) or switch is tagged by pressing the SLD pushbutton
“Tag”. If the selected switching device is tagged, a letter “T” appears under its symbol.
Tagging can be achieved in local mode using the front panel control from the configurable
SLD screens. The Pushbutton “Tag” logic diagram shows the tagging logic diagram for a
switch. The logic applies to one breaker or switch at the time in the single line diagram.
894198A1.cdr
FLEXLOGIC OPERAND
BKR [X] Selected
SW [X] Selected
AND
S
Latch
R
Non-Volatile Latch
Reset- Dominant
positive
one shot
Byp Blk
PB “BYPASS
BLOCK”
AND
FLEXLOGIC OPERAND
Bypass Block ON
FLEXLOGIC OPERAND
Bypass Block OFF
OR
FLEXLOGIC OPERAND
SBO Enabled
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