EMR-5000
IM02602012E
Load Shedding
Available elements:
MLS
Functional Description
In some applications, the protective device can forestall a JAM alarm or trip, or a thermal trip, by sending a signal to the
process to reduce loading. The load shedding function, if enabled, closes or opens a relay contact to shed process
load when the motor load current goes above the Load Shed Drop threshold, for a time exceeding the Drop Delay t.
This could, for example, be connected to stop flow of material into the driven process until the load current drops below
the Load Shed Dropout threshold, for the time determined by the Drop Delay t.
Set the load shed pickup current comfortably below the JAM trip level. It may be useful to set it below the Ultimate Trip
Current, particularly if RTDs are not used.
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 protective device 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 settings “MLS -
Mechanical Load Shedding”, under each of the the Setting groups (Set 1 for example).
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