GE Multilin M60 Motor Protection System 5-179
5 SETTINGS 5.6 GROUPED ELEMENTS
5
• UNDERPOWER 1 TRIP PICKUP DLY: This setting specifies a time delay for the trip stage. This time delay should be
long enough to overcome any short lowering of the current (for example, during system faults).
• UNDERPOWER 1 TRIP RESET DLY: This setting specifies a time delay to reset the trip command. This delay should
be set long enough to allow breaker or contactor to disconnect the motor.
• UNDERPOWER 1 BLOCK: This setting specifies an operand used to block the underpower function. A panel cutoff
switch or other user specified condition is typically used to block the function.
Figure 5–84: UNDERPOWER LOGIC
833025A1.CDR
Sop = sum (Sa + Sb + Sc)
SETTING
=Ia
=Ib
MOTOR LINE SOURCE
=Ic
VOLTAGE CONNECTION
Vab
Wye Delta
Vca
Vbc
Vag
Vcg
Vbg
CALCULATE
FLEXLOGIC OPERAND
MOTOR OFFLINE
AND
AND
AND
=Off
UNDERPOWER 1 BLOCK
SETTINGS
= Enabled
UNDERPOWER 1
FUNCTION
COMPARATORS
magnitude Ia > 0.1 × FLA
magnitude Ib > 0.1 × FLA
magnitude Va > 0.25 pu
magnitude Ic > 0.1 × FLA
magnitude Vb > 0.25 pu
magnitude Vc > 0.25 pu
AND
T
PKP
0
SETTING
UNDERPOWER 1 START
BLOCK DLY
AND
SETTINGS
UNDERPOWER 1 ALARM
PWR PICKUP
RUN
Sop < ALARM PICKUP
RUN
Sop < TRIP PICKUP
UNDERPOWER 1 TRIP
PWR PICKUP
SETTINGS
UNDERPOWER 1 TRIP
PICKUP DLY
UNDERPOWER 1 TRIP
RESET DLY
T
PKP
0
UNDERPOWER 1 ALARM
PICKUP DLY
T
PKP
T
RST
FLEXLOGIC OPERAND
UNDERPWR 1 ALARM OP
FLEXLOGIC OPERANDS
UNDERPWR 1 ALARM PKP
UNDERPWR 1 ALARM DPO
UNDERPWR 1 TRIP PKP
UNDERPWR 1 TRIP DPO
FLEXLOGIC OPERAND
UNDERPWR 1 TRIP OP
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