Date Code 20010719 701 Motor Protection Relay
Event Analysis
Front-Panel Target LEDs
9.3
Resetting Front-Panel Targets
To reset the front-panel tripping targets, select the Reset Trip/Targets function
from the front-panel display main menu, or execute the serial port TARGET R
command. When you reset the relay targets using one of these methods:
All tripping LEDs are extinguished if the trip condition has vanished
and no lockout conditions remain.
The front-panel display trip message (described in Front-Panel
Messages on page 9.4) is cleared.
NOTE: If you try to reset the relay targets and one or more of the
red LEDs remains lit after the target reset command, the
tripping condition or a lockout condition is still present.
Correct the condition that caused the relay to trip and try
again.
NOTE: The factory default relay logic causes relay trip signals to
remain latched after the fault is cleared until you reset the
relay targets. If this performance is not acceptable for your
application, refer to Appendix B: SELogic® Control Equations &
Relay Logic for instructions on changing the factory default
relay logic settings.
When you reset the LEDs using the front-panel menu function, the relay
illuminates all the LEDs as a lamp test before clearing the targets.
Motor Energized LED
The Motor Energized LED is dark, flashes, or remains on to indicate the stopped,
starting, or running condition of the motor. The relay determines the motor condition
by measuring the positive-sequence current (I
1
) and comparing the magnitude of the
current to several thresholds defined by the Full Load Amps (FLA) setting.
STOPPED. When motor positive-sequence current is less than 10% of the Full
Load Amps setting, the relay declares the motor stopped. The Motor
Energized LED is dark.
STARTING. If the motor was stopped and now positive-sequence current is
greater than 250% of the Full Load Amps setting, the relay declares the
motor starting. The Motor Energized LED flashes.
RUNNING. If the positive-sequence current is between 10% and 250% of the
Full Load Amps setting, the relay declares the motor running. The Motor
Energized LED remains on.
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