Against Thermal Overload - ABB ACS355 series User Manual

46 Planning the electrical installation
Protecting the drive, input power cable, motor and motor
cable in short-circuit situations and against thermal
overload

Protecting the drive and input power cable in short-circuit situations
Arrange the protection according to the following guidelines.
Distribution
board
1)
1)
Size the fuses or manual motor protectors (MMP) according to instructions given in chapter
Technical data on page 373. The fuses or MMPs will protect the input cable in short-circuit
situations, restrict drive damage and prevent damage to adjoining equipment in case of a
short-circuit inside the drive.

Protecting the motor and motor cable in short-circuit situations
The drive protects the motor and motor cable in a short-circuit situation when the
motor cable is dimensioned according to the nominal current of the drive. No
additional protection devices are needed.

Protecting the drive, motor cable and input power cable against
thermal overload
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 must be used for protecting each cable and motor. These
devices may require a separate fuse to cut off the short-circuit current.
Circuit diagram
Input cable Drive
M
3~
Short-circuit protection
Protect the drive and input
cable with fuses. See
footnote 1).