CHAPTER 5: SETTINGS
469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL
5–61
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
SHORT CIRCUIT TRIP PICKUP
was
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.
5.7.2
Overload Alarm
PATH: SETTINGS
S6 CURRENT ELEM.
OVERLOAD ALARM
If enabled as “Latched” or “Unlatched”, the Overload Alarm functions as follows. After a
motor start, when the equivalent motor heating current exceeds the
OVERLOAD PICKUP
LEVEL
, an alarm will occur. If programmed as “Unlatched”, the overload alarm resets itself
when the motor is no longer in overload. If programmed as “Latched”, the
RESET
key must
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.
5.7.3
Mechanical Jam
PATH: SETTINGS
S6 CURRENT ELEM.
MECHANICAL JAM
OVERLOAD
[
]
ALARM
OVERLOAD
ALARM: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN ALARM RELAYS:
Alarm
Range: Alarm, Auxiliary2, Auxiliary3,
Alarm & Aux2, Alarm & Aux3,
Aux2 & Aux3, Alarm & Aux2 &
Aux3, None
MESSAGE
OVERLOAD ALARM
DELAY: 0.1 s
Range: 0.1 to 60 s in steps of 0.1
MESSAGE
OVERLOAD ALARM
EVENTS: Off
Range: On, Off
MECHANICAL [
]
JAM
MECHANICAL JAM
TRIP: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN TRIP RELAYS:
Trip
Range: Trip, Trip & Auxiliary2, Trip &
Aux2 & Aux3, Trip & Auxiliary3
MESSAGE
MECHANICAL JAM
PICKUP: 1.50 x FLA
Range: 1.01 to 3.00 x FLA in steps of
0.01
MESSAGE
MECHANICAL JAM
DELAY: 1 s
Range: 1 to 30 s in steps of 1
Summary of Contents for Masoneilan 469 Series
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Page 92: ...3 28 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 3 INSTALLATION ...
Page 256: ...5 112 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 5 SETTINGS ...
Page 298: ...6 42 469 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL CHAPTER 6 ACTUAL VALUES ...
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