Acs580, Ach580 And Acq580; Implementing A Bypass Connection; Protecting The Contacts Of Relay Outputs - ABB ACS880 Electrical Planning Instructions

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.
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ACS580, ACH580 and ACQ580

When you have selected to use
• 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 decelerates the motor to zero speed.
3. Open the contactor.
When you have selected to use
• vector 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 vector control mode is in use, never open the output contactor while the
drive controls the motor. The vector 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 vector 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.

Implementing a bypass connection

If bypassing is required, employ 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. The installation must be
clearly marked as defined in IEC/EN 61800-5-1, subclause 6.5.3, for example, "THIS
MACHINE STARTS AUTOMATICALLY".
Bypass connection is available as a factory-installed option for some cabinet-installed drive
types. Consult ABB for more information.
WARNING!
Never connect the drive output to the electrical power network. The connection
may damage the drive.

Protecting the contacts of relay outputs

Inductive loads (relays, contactors, motors) cause voltage transients when switched off.
Electrical planning guidelines 33