Permanent Magnet Synchronous Motor; Thermal Overload And Short-Circuit Protection; Fuses; Earth Fault (Ground Fault) Protection - ABB ACS 800-17 Hardware Manual

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Permanent magnet synchronous motor

Only one permanent magnet motor can be connected to the inverter output.
Install a safety switch between a permanent magnet synchronous motor and the
motor cable. The switch is needed to isolate the motor during any maintenance work
in the drive.
Wire the position information of the safety switch to the drive. Before starting any
maintenance work on the drive, the safety switch must be opened, and the open
position acknowledged by the drive application program.

Thermal overload and short-circuit protection

The drive protects itself and the input and motor cables against thermal overload
when the cables are dimensioned according to the nominal current of the drive. No
additional thermal protection devices are needed.
WARNING! If the drive is connected to multiple motors, a separate thermal overload
switch or a circuit breaker must be used for protecting each cable and motor. These
devices may require a separate fuse to cut off the short-circuit current.
The drive protects the motor cable and the motor in a short-circuit situation when the
motor cable is dimensioned according to the nominal current of the drive.

Fuses

Fuses are needed to protect the supply section and the inverter of the drive in case
of an internal short-circuit. The ACS800-17 is equipped with internal input fuses
introduced in chapter
similar ultrarapid fuse.
WARNING! Circuit breakers are not capable of providing sufficient protection
because they are inherently slower than fuses. Always use fuses with circuit
breakers.

Earth fault (Ground fault) protection

Both the supply unit and the inverter unit are equipped with an internal earth fault
protective function to protect the drive against earth faults in the motor and the motor
cable. (This is not a personal safety or a fire protection feature.) Both earth fault
protective functions can be disabled; refer to User's Manual of the supply unit and
the Firmware Manual of the drive application program respectively.
See the ACS800 Ordering Information (code: 64556568 [English], available on
request) for other available earth fault protection options.
Planning the electrical installation
Technical data. If a fuse is blown, it must be replaced with a