ABB ACS880-04FXT, Hardware Manual

Page: 76 / 196

Protecting the drive and input cable in short-circuits and
against thermal overload
￭ Protecting the drive and the input power cable in short-circuits
Protect the drive (1) with fuses (a) and the input cable with fuses (b) or a circuit breaker.
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M
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b a
1
Equip the fuses with blown fuse indicators (microswitches) for stopping the drive. For
instructions, see
Wiring the microswitches of the fuses (page 99) .
Size the fuses or the circuit breaker according to local regulations for the input cable
protection. Select the fuses for the drive according to the instructions given in the technical
data. The fuses for the drive protection will restrict drive damage and prevent damage to
adjoining equipment in case of a short-circuit inside the drive.
Circuit breakers
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. Your local ABB representative can help you in selecting the breaker
type when the supply network characteristics are known.
WARNING!
Due to the inherent operating principle and construction of circuit breakers,
independent of the manufacturer, hot ionized gases can escape from the breaker
enclosure in case of a short-circuit. To ensure safe use, pay special attention to
the installation and placement of the breakers. Obey the manufacturer’s instructions.
Circuit breakers must not be used without fuses.
￭ Protecting the drive and the input power cable against thermal overload
The drive protects itself and the input power cable against thermal overload when the cables
are dimensioned according to the nominal current of the drive. No additional thermal
protection devices are needed.
In 6-pulse connection with a common main circuit breaker, the drive protects the input cables
against thermal overload when the cables are dimensioned according to the nominal current
of the drive.
For 12-pulse connection and 6-pulse connection with individual circuit breakers, use gG
fuses with blown fuse indicators for the thermal protection of the input cables. Wire the
indicators to stop the drive in case of a blown fuse.
76 Guidelines for planning the electrical installation