O Verload A Larm - GE 469 Instruction Manual

CHAPTER 5: SETTINGS
5.7.2 Overload Alarm
 OVERLOAD
ALARM
5.7.3 Mechanical Jam
 MECHANICAL []
JAM
469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL
be increased if nuisance tripping occurs.
When a motor starts, the starting current (typically 6 × FLA for an induction motor) has an
asymmetrical component. This asymmetrical current may cause one phase to see as
much as 1.6 times the normal RMS starting current. If the
set at 1.25 times the symmetrical starting current, it is probable that there would be
nuisance trips during motor starting. A rule of thumb has been developed over time that
short circuit protection at least 1.6 times the symmetrical starting current value. This
allows the motor to start without nuisance tripping.
The overreach filter removes the DC component from the asymmetrical current present at
the moment of fault. This eliminates overreach; however, the response time slows slightly
(10 to 15 ms) but remains within specification.

PATH: SETTINGS S6 CURRENT ELEM.
[] OVERLOAD
ALARM: Off
ASSIGN ALARM RELAYS:
MESSAGE
Alarm
OVERLOAD ALARM
MESSAGE
DELAY: 0.1 s
OVERLOAD ALARM
MESSAGE
EVENTS: Off
If enabled as "Latched" or "Unlatched", the Overload Alarm functions as follows. After a
motor start, when the equivalent motor heating current exceeds the
, an alarm will occur. If programmed as "Unlatched", the overload alarm resets itself
LEVEL
when the motor is no longer in overload. If programmed as "Latched", the
be pressed to reset the alarm once the overload condition is gone. Event recording for all
alarm features is optional.
For example, it may be desirable to have an unlatched alarm connected to a PLC that is
controlling the load on a motor.

PATH: SETTINGS S6 CURRENT ELEM.
MECHANICAL JAM
TRIP: Off
ASSIGN TRIP RELAYS:
MESSAGE
Trip
MECHANICAL JAM
MESSAGE
PICKUP: 1.50 x FLA
MECHANICAL JAM
MESSAGE
DELAY: 1 s
SHORT CIRCUIT TRIP PICKUP

OVERLOAD ALARM
Range: Off, Latched, Unlatched
Range: Alarm, Auxiliary2, Auxiliary3,
Alarm & Aux2, Alarm & Aux3,
Aux2 & Aux3, Alarm & Aux2 &
Aux3, None
Range: 0.1 to 60 s in steps of 0.1
Range: On, Off

MECHANICAL JAM
Range: Off, Latched, Unlatched
Range: Trip, Trip & Auxiliary2, Trip &
Aux2 & Aux3, Trip & Auxiliary3
Range: 1.01 to 3.00 x FLA in steps of
0.01
Range: 1 to 30 s in steps of 1
was
OVERLOAD PICKUP
key must
RESET
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