ABB ACS880-11, Hardware Manual

Page: 77 / 232

Note: As standard, the drive contains capacitors connected between the main circuit
and the frame. These capacitors and long motor cables increase the ground leakage
current and may cause nuisance faults in residual current devices.
Implementing the emergency stop function
For safety reasons, install the emergency stop devices at each operator control station
and at other operating stations where emergency stop may be needed. Implement the
emergency stop according to relevant standards.
Note: You can use the Safe torque off function of the drive to implement the Emergency
stop function.
Implementing the Safe torque off function
See The Safe torque off function (page 209) .
Implementing the power loss ride-through function
If the incoming supply voltage is cut off, the drive will continue to operate by utilizing
the kinetic energy of the rotating motor. The drive will be fully operational as long as the
motor rotates and generates energy to the drive.
If you equip the drive with a main contactor or breaker, make sure that it restores the
drive input power after a short break. The contactor must either re-connect after the
break automatically, or remain closed over the break. Depending on the contactor control
circuit design, this can require an additional hold circuit, uninterruptible auxiliary power
supply or auxiliary power supply buffering.
Note that if the power loss lasts so long that the drive trips on undervoltage, a fault reset
and a fresh start command is required to continue operation.
Implement the power-loss ride-through function as follows:
1. Enable the power-loss ride-through function of the drive (parameter 30.31 ).
2. If the installation is equipped with a main contactor, prevent its tripping at the input
power break. For example, use a time delay relay (hold) in the contactor control
circuit.
3. Enable the automatic restart of the motor after a short power supply break:
• Set the start mode to automatic (parameter 21.01 or 21.19 , depending on the
motor control mode being used).
• Define the automatic restart time (parameter 21.18 ).
WARNING!
Make sure that a flying restart of the motor will not cause any danger. If you are
in doubt, do not implement the power loss ride-through function.
Guidelines for planning the electrical installation 77