ABB ACS880-87LC-4000A/4021A-7, Hardware Manual

Page: 64 / 144

64 Planning the electrical installation
Using a safety switch between the converter and
generator
To minimize the emission level when safety switches are installed in the generator cable
between the converter and the generator:
•
Install the equipment in a metal enclosure in a way that the conduit or generator cable
shielding runs consistently without breaks from the converter to the generator.
Using a contactor between the converter and generator
(F269)
Note: Select this option selected if you use the wind turbine converter with a permanent
magnet generator.
If you install a contactor between the converter and generator:
•
install the contactor inside a metal enclosure
•
keep the shield and any protective ground (PE) conductors continuous (connect the
incoming and outgoing shields / PE conductors)
•
when the DTC generator control mode is in use: make sure that it is not possible to
open the contactor while the converter is in operation. The contactor may be opened
only after a stop command is given to the generator-side converter. Otherwise the
contactor may be damaged.
Protecting the contacts of relay outputs
Inductive loads (such as relays, contactors and generators) cause voltage transients when
switched off.
The relay contacts of the control board are protected with varistors (250 V) against
overvoltage peaks. In spite of this, it is highly recommended to equip inductive loads with
noise attenuating circuits (varistors, RC filters [AC] or diodes [DC]) in order to minimize the
EMC emission at switch-off. If not suppressed, the disturbances may connect capacitively
or inductively to other conductors in the control cable and form a risk of malfunction in
other parts of the system.