Using A Contactor Between The Drive And The Motor - ABB ACS800 Series Hardware Manual

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Using a contactor between the drive and the motor

Implementing the control of the output contactor depends on how you select the
drive to operate.
When you have selected to use DTC motor control mode, and motor ramp stop,
open the contactor as follows:
1. Give a stop command to the drive.
2. Wait until the drive decelerates the motor to zero speed.
3. Open the contactor.
When you have selected to use DTC motor control mode, and motor coast stop, or
scalar control mode, open the contactor as follows:
1. Give a stop command to the drive.
2. Open the contactor.
WARNING! When the DTC motor control mode is in use, never open the output
contactor while the drive controls the motor. The DTC motor control operates
extremely fast, much faster than it takes for the contactor to open its contacts. When
the contactor starts opening while the drive controls the motor, the DTC control will
try to maintain the load current by immediately increasing the drive output voltage to
the maximum. This will damage, or even burn the contactor completely.
Planning the electrical installation