ABB ACS880-M04, Hardware Manual

Page: 68 / 195

68 Planning the electrical installation
Implementing the Power-loss ride-through function
See ACS880-M04 firmware manual (3AXD50000030629 (English]).
Using a safety switch between the drive and the motor
Install a safety switch between the permanent magnet motor and the drive output.
The safety switch isolates the motor from the drive during maintenance work on the
drive.
Using a contactor between the drive and the motor
The control of the output contactor depends on how you use the drive. See also
Implementing a bypass connection on page 68 .
When you use the vector control mode and motor ramp stop, open the contactor as
follows:
1. Give a stop command to the drive.
2. Wait until the drive stops the motor.
3. Open the contactor.
When you use the vector control mode and motor coast stop or the scalar control
mode, open the contactor as follows:
1. Give a stop command to the drive.
2. Open the contactor.
WARNING! In vector control mode, do not open the output contactor when the
drive controls the motor. The vector control operates faster than the contactor
opens its contacts.
If the contactor starts to open when the drive controls the motor, the vector control
tries to maintain the load current and increases the drive output voltage to the
maximum. This can cause damage to the contactor.
Implementing a bypass connection
If the drive needs to be bypassed frequently, use mechanically or electrically
interlocked contactors between the motor and the drive and between the motor and
the power line. Make sure with interlocking that the contactors cannot be closed
simultaneously. See the example below.
WARNING! Do not connect the drive output to the electrical power network.
This can cause damage to the drive.