Page 60 I.L. 17562
PR 0.3 Effective 8/99
5.9 Page 9, SP AUX1, Setpoints P9L1 to P9L25 — Use this page to configure which events
activate the AUX1 output relay. It also includes the three setpoints to configure the load
shedding function.
The factory default setting is for a thermal trip (I2T trip) only to pick up this relay. Many users
will choose to change this. If the load shed function is turned on, using settings P9L1 to P9L3 as
explained next, the relay AUX1 is dedicated to this function and other uses are not available or
visible.
The load shed function provides a contact output signal that the user connects to the process
equipment, to reduce loading on the motor if it becomes too large. For example, the contact
might be used to temporarily stop the flow of heavy materials onto a conveyor driven by the
protected motor. In this way, the MP-3000 tries to alleviate an overload before it reaches an
outright thermal protective trip. When the load is reduced, the contact returns to the normal
state and the process can resume loading of the motor.
The load shed function, which is active only during the RUN state of the motor, is configured with
the following three setpoints:
5.9.1 Setpoint P9L1, Load Shed Pickup Current (LSPU) — Sets current level above which the
load shed output is activated.
5.9.2 Setpoint P9L2, Load Shed Dropout Current (LSDO) — Sets current level below which
the load shed output is deactivated.
5.9.3 Setpoint P9L3, Load Shed Delay (LSDL) — Sets both the pickup and dropout delays in
seconds for the load shed output. In other words, it sets the time for which the current must be
above LSPU before the output is activated; and also sets the time for which the current must be
below LSDO before the output is deactivated.
The LSPU and LSDO setpoints are forced to be coherent:
• If the user sets either to OFF, the other is automatically set to OFF as well.
• If LSPU is set to any pickup value with LSDO OFF then LSDO is set to its minimum on-
setting, 50 percent of FLA. User can then set it to a different value if desired.
• If LSDO is set to any dropout value with LSPU OFF then the LSPU is set to its maximum
value, 150 percent of FLA. User can then set it to a different value if desired.
• LSPU must be greater than LSDO. Setting range of either may be limited to enforce this.
5.9.4 Setpoints P9L4 through P9L25, Alarm and Trip assignments to AUX1 - If LSPU and
LSDO are both set to OFF, all other available functions for AUX1 become visible and can be
individually turned on or off. AUX1 is activated if any of the designated functions picks up, with
an OR logic function. Other than the three load shed function setpoints, the remaining setpoints
are the same as the 22 listed for SP AREL page in Section 5.8. The AUX1 output operates if
any of the selected functions become true.
5.10 Page 10, SP AUX2, Setpoints P10L1 to P10L23 — This page determines which events
activate the output relay AUX2. It also includes the setpoint to enable the transition function.
The factory settings configure AUX2 to pick up for the transition function.
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