OPERATION
Protection Features
Insulation Check
Insulation check is performed when the motor is off, just prior to a motor start command.
The SubMonitor Connect checks the resistance of a motor winding (W) to ground by applying a DC
voltage to the motor winding just prior to motor start. Leakage current is measured by the SubMonitor
Connect and a resistance measurement is calculated.
This output trips if the measured insulation resistance on the motor winding is less than the resistance
trip threshold setting.
The default setting is off; the default alarm activation is at a reading of 1000 kΩ; a default Fault is
indicated when the reading is 500 kΩ.
Insulation Check connection diagrams for MT1111/6111 (left) and MT1311/2211 (right):
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