Thermal Overload And Short-Circuit Protection; Mains Cable (Ac Line Cable) Short-Circuit Protection; Acs800-04/U4; Drive Ac Fuses (Acs800-07/U7, And Acs800-02/U2 With Enclosure Extension) - ABB ACS800 Hardware 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.

Mains 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
Technical Data).
ACS800-01/U1, ACS800-11/U11, ACS800-02/U2 without enclosure extension and

ACS800-04/U4

When placed at the distribution board, standard gG (US: CC or T for the ACS800-
U1; T or L for the ACS800-U2 and ACS800-U4) 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.

Drive AC fuses (ACS800-07/U7, and ACS800-02/U2 with enclosure extension)

ACS800-07/U7 units and ACS800-02/U2 units with enclosure extension are
equipped with standard gG (US: T/L) or optional aR fuses listed in Technical Data.
The fuses 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 (gG or aR), supply network impedance and the cross-
sectional area, material and length of the supply cable. In case the 0.5 seconds
operating time is exceeded with gG (US: CC/T/L) fuses, ultrarapid (aR) fuses will in
most cases reduce the operating time to an acceptable level. The US fuses must be
of the "non-time delay" type.
For fuse ratings, see Technical Data.
Planning the electrical installation