ABB ACS800-67LC, Hardware Manual

Page: 64 / 154

64 Planning the electrical installation
Protecting the converter, grid cable, rotor and rotor
cable in short-circuit situation and against thermal
overload

Protecting the grid cable in short-circuit situations
Protect the grid cable with fuses.
Size the fuses according to local safety regulations, appropriate input voltage and rated
current of the converter. Check that the operating time of the fuses is below 0.5 seconds.
WARNING! Circuit breakers are not capable of providing sufficient protection
because they are inherently slower than fuses. Always use fuses with circuit
breakers.

Protecting the converter in short-circuit situations
AC fuses
Always protect the converter with AC fuses listed in chapter Technical data . The fuses
restrict the converter damage and prevent damage to adjoining equipment. The fuses are
included in the delivery of the wind turbine converter automatically if it is equipped with
400 mm wide incoming cubicle (C111), or a power cabinet (C108 or
+C109). For the other units, the fuses must be acquired and installed outside the converter
cabinet by the user.
WARNING! Circuit breakers are not capable of providing sufficient protection
because they are inherently slower than fuses. Always use appropriate fuses.
DC fuses
The converter employs fuses in the DC link between the grid-side and rotor-side converter
modules. See
chapter Technical data for fuse ratings.

Protecting the rotor and rotor cable in short-circuit situations
The converter is capable of detecting a short-circuit in generator rotor windings or in
generator rotor cable. However, it does not protect the generator or generator cables.

Protecting the converter, grid cable and rotor cable against thermal
overload
The converter protects itself, the grid cable and rotor cable against thermal overload when
the cables are dimensioned according to the nominal current of the converter and the
ambient conditions are within the limits specified in section
Ambient conditions on page
128 .
Power supply
network
to rotor
Grid-side converter AC fuses
DC fuses