Fuses; Thermal Overload And Short-Circuit Protection; Mains Cable (Ac Line Cable) Short-Circuit Protection; Ground Fault Protection - ABB ACS800-U4 Hardware Manual

US
The disconnecting means must conform to the applicable safety regulations.

Fuses

See section

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.

Mains cable (AC line cable) short-circuit protection

Always protect the input cable with fuses. Standard gG (US: CC or T for the
ACS800-U1; T or L for the ACS800-U2
input cable in short-circuit situations and prevent damage to adjoining equipment in
case of a short-circuit inside the drive. The US fuses must be of the "non-time delay"
type.
Size the fuses according to local safety regulations, appropriate input voltage and
the rated current of the drive. For fuse ratings, see Technical Data.
WARNING! Circuit breakers are not capable of providing sufficient protection
because they are inherently slower than fuses. Always use fuses with circuit
breakers.

Ground fault protection

The drive is equipped with an internal ground fault protective function to protect the
unit against ground faults in the motor and the motor cable. This is not a personal
safety or a fire protection feature. The ground fault protective function can be
disabled with a parameter, refer to the appropriate ACS 800 Firmware Manual.
The EMC filter of the drive includes capacitors connected between the main circuit
and the frame. These capacitors and long motor cables increase the ground leakage
current and may cause fault current circuit breakers to function.
Thermal overload and short-circuit protection.
and the ACS800-U4) fuses will protect the
Electrical installation planning
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