Thermal Overload And Short-Circuit Protection - ABB ACS150 User Manual

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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 motor in a short-circuit situation when the
motor cable is dimensioned according to the nominal current of the drive.
Input power cable (AC line cable) short-circuit protection
Always protect the input cable with fuses. Size the fuses according to local safety
regulations, appropriate input voltage and the rated current of the drive (see chapter
Technical
When placed at the distribution board, standard IEC gG fuses or UL type T fuses 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.
Operating time of the fuses
Check that the operating time of the fuse is below 0.5 seconds. The operating
time depends on the fuse type, the supply network impedance and the cross-
sectional area, material and length of the supply cable. The US fuses must be of the
"non-time delay" type.
For fuse ratings, see chapter
Circuit breakers (To be defined)
Circuit breakers which have been tested by ABB with the ACS150 can be used.
Fuses must be used with other circuit breakers. Contact your local ABB
representative for approved breaker types and supply network characteristics.
The protective characteristics of circuit breakers depend on the type, construction
and settings of the breakers. There are also limitations pertaining to the short-circuit
capacity of the supply network.
Planning electrical installation
data).
Technical data.