I.L. 17562
Page 53
PR 0.3 Effective 8/99
5.3.3 Setpoint P3L3, Ground Fault Run Delay (GFRD) — Sets the number of power cycles
that a ground fault trip or alarm operation must be maintained before the relay produces an
output.
5.3.4 Setpoint P3L4, Instantaneous Overcurrent Trip Level (IOC) — Sets the instantaneous
overcurrent trip limit in percent of FLA above which the relay will trip. This trip type can be set to
OFF. For currents clearly above the setting, the IOC function picks up in two power cycles or
less. IOC operates only for high-current faults, and no run delay is needed. Use with IOC Start
Delay. Normally, set IOC above 1.5 times LRC. See Section 9.1.3.1.
The IOC setting must be below (1020 * PCT/ FLA) or 1600%, whichever is less. PCT is Setpoint
P1L5; FLA is Setpoint P1L1. If this constraint is exceeded, you will not be able to exit program
mode, but will get a specific warning message instead.
5.3.5 Setpoint P3L5, Instantaneous Overcurrent Start Delay (IOCSD) — Sets the number of
power cycles after a start is recognized until the instantaneous overcurrent trip and alarm
functions are enabled. Use this delay to inhibit IOC tripping on a current peak caused by
magnetic inrush when the motor is first energized - usually one to three cycles.
5.3.6 Setpoint P3L6, Jam Trip Level (JMT) — Sets the motor jam current trip limit in percent of
FLA. This element can be set to OFF. Use with the jam start and run delays.
The jam trip function operates if the current rises well above FLA during running, perhaps due to
a mechanical jam in the load or a sudden larger-than-intended load. For example, see the jam
trip limits set at 180% of FLA in the upper RUN portions of protection curves of Figures 9.4 or
9.5.
The JMT setpoint must be below (1020 * PCT/ FLA) or 1200%, whichever is less. PCT is
Setpoint P1L5; FLA is Setpoint P1L1. If this constraint is exceeded, you will not be able to exit
program mode, but will get a specific warning message instead.
5.3.7 Setpoint P3L7, Jam Start Delay (JMSD) — Sets the number of seconds after a start is
recognized until the jam trip and alarm functions are enabled.
Use JMSD to block jam trips during starting. Use even longer values in high-inertia load
situations where the acceleration time is longer than the start time. In these cases, the motor
current may remain above FLA or JMT for some time after the transition from start to run.
5.3.8 Setpoint P3L8, Jam Trip Run Delay (JMTR) — Sets the number of seconds that a jam
trip current level must be maintained before the trip output occurs.
Use JMTR to block undesired jam trips for temporary large loads which are normal for the
process - for example, a heavy load suddenly being placed on the conveyor belt which the motor
must accelerate.
5.3.9 Setpoint P3L9, Underload Trip Level (ULT) — Sets the current level in percent of FLA
below which the MP-3000 determines that the motor has lost its load and trips the motor. This
element can be set to OFF. Use with the underload start and run delays.
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