S9 Voltage Elements; Undervoltage - GE 469 Instruction Manual

4 SETPOINTS

4.10S9 VOLTAGE ELEMENTS

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PATH: SETPOINTS S9 VOLTAGE ELEMENTS
n UNDERVOLTAGE
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The
U/V ACTIVE ONLY IF BUS ENERGIZED
gized. If this setpoint is programmed to "Yes", at least one voltage must be greater than 20% of the nominal nameplate volt-
age rating for any alarm/trip. If the load is high inertia, it may be desirable to trip the motor off-line or prevent it from starting
in the event of a total loss of line voltage. Programming "No" for this setpoint ensures that the motor is tripped and may be
restarted only after the bus is re-energized.
If the undervoltage alarm or trip feature is enabled, once the magnitude of either Va, Vb, or Vc falls below the pickup level
while running or starting pickup level while starting (for a period of time specified by the delay), a trip or alarm will occur
(pickup levels are multiples of motor nameplate voltage). The running pickup level also applies when the motor is stopped
and the
U/V ACTIVE ONLY IF BUS ENERGIZED
An undervoltage on a running motor with a constant load results in increased current. The relay thermal model typically
picks up this condition and provides adequate protection. However, this setpoint may be used in conjunction with the time
delay to provide additional protection that may be programmed for advance warning by tripping.
Attempting to start a large motor when the supply voltage is already down may also be undesirable. An undervoltage of sig-
nificant proportions that persists while starting a motor may prevent the motor from coming up to rated speed. This may be
especially critical for a synchronous motor. This feature may be used in with a time delay to provide protection for under-
voltage conditions before and during starting.
GE Multilin
Courtesy of NationalSwitchgear.com
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UNDERVOLTAGE

ð
U/V ACTIVE ONLY IF
ENTER
ESCAPE BUS ENERGIZED: No
UNDERVOLTAGE
ESCAPE
ALARM: Off
MESSAGE
ASSIGN ALARM RELAYS:
ESCAPE
Alarm
MESSAGE
UNDERVOLTAGE ALARM
ESCAPE
PICKUP: 0.85 x RATED
MESSAGE
STARTING U/V ALARM
ESCAPE
PICKUP: 0.85 x RATED
MESSAGE
UNDERVOLTAGE ALARM
ESCAPE
DELAY: 3.0 s
MESSAGE
UNDERVOLTAGE ALARM
ESCAPE
EVENTS: Off
MESSAGE
UNDERVOLTAGE
ESCAPE
TRIP: Off
MESSAGE
ASSIGN TRIP RELAYS:
ESCAPE
Trip
MESSAGE
UNDERVOLTAGE TRIP
ESCAPE
MESSAGE PICKUP: 0.80 x RATED
STARTING U/V TRIP
ESCAPE
PICKUP: 0.80 x RATED
MESSAGE
UNDERVOLTAGE TRIP
ESCAPE
DELAY: 3.0 s
MESSAGE
setpoint may be used to prevent nuisance alarms or trips when the bus is not ener-
setpoint is programmed to "No".
469 Motor Management Relay
4.10 S9 VOLTAGE ELEMENTS
4.10.1 UNDERVOLTAGE
Range: No, Yes
Range: Off, Latched, Unlatched
Range: Alarm, Alarm & Auxiliary2, Alarm & Aux2 & Aux3,
Alarm & Auxiliary3, Auxiliary2, Aux2 & Aux3,
Auxiliary3
Range: 0.60 to 0.99 x RATED in steps of 0.01
Range: Off, 0.60 to 0.99 x RATED in steps of 0.01
Range: 0.0 to 60.0 s in steps of 0.1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Trip, Trip & Auxiliary2, Trip & Aux2 & Aux3,
Trip & Auxiliary3
Range: 0.60 to 0.99 x RATED in steps of 0.01
Range: 0.60 to 0.99 x RATED in steps of 0.01
Range: 0.0 to 60.0 s in steps of 0.1
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