12.16 Undervoltage Protection; Other Considerations - GE Multilin 469 Quick Reference Manual

SYSTEM DATA

12.16 Undervoltage Protection:

58
RTD #1 ALARM TEMPERATURE
: "Off"
RTD #1 HIGH ALARM
: "Alarm" - default value
HIGH ALARM RELAYS
RTD #1 HIGH ALARM TEMPERATURE
RTD #1 ALARM EVENTS
: "Latched"
RTD #1 TRIP
: "RTD #5"
RTD #1 TRIP VOTING
: "Trip"
ASSIGN TRIP RELAYS
RTD #1 TRIP TEMPERATURE
The settings for the other RTDs are entered in similar fashion.
In addition to the settings illustrated above, there will be cases in motor applications where
additional settings will be required, to monitor other system parameters such as voltage
levels.
The following sub-section will illustrate the procedures to set the 469 Motor Management
Relay to meet those requirements.
Using the same system information, the following example illustrates the steps to set the
469 for Undervoltage protection.
The following setpoints are provided:
Pickup: 70% of nominal voltage – starting
80% of nominal voltage – running
Time Delay: 13.0 s

Other Considerations:

• The function will be active only if there is voltage in the line feeding the motor, to avoid
nuisance trips due to the lack of voltage. The 469 will consider the bus energized only
if the measured voltage is greater than 20% of nominal voltage. A trip condition will be
initiated only if undervoltage is detected in all the phases.
• In order to monitor for VT Fuse Failure or to monitor for undervoltage in one phase
only, set an Alarm when the voltage is 90% of nominal voltage both during start and
running.
For the Undervoltage element, enter the following values in the
setpoints page. Press the
UNDERVOLTAGE
key, after each setpoint is completed, to move to the next message:
U/V ACTIVE ONLY IF BUS ENERGIZED
UNDERVOLTAGE ALARM
ASSIGN ALARM RELAYS
UNDERVOLTAGE ALARM PICKUP
STARTING U/V ALARM PICKUP
UNDERVOLTAGE ALARM DELAY
UNDERVOLTAGE ALARM EVENTS
: "Latched"
UNDERVOLTAGE TRIP
UNDRVOLTAGE TRIP MODE
: "Trip"
ASSIGN TRIP RELAYS
: "135°C"
: "135°C" - default value
: "On"
: "155°C"
key to save, and then the
ENTER
: "Yes"
: "Unlatched"
: "Alarm"
: "0.9 x RATED"
: "0.9 x RATED"
: "0.0 s"
: "Yes"
: "3-Phase"
469 MOTOR MANAGEMENT RELAY – QUICK REFERENCE GUIDE
QUICK REFERENCE GUIDE
S9 VOLTAGE ELEMENTS
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