ABB ACS880-87LC-4000A/4021A-7, Руководство по оборудованию

Страница: 56 / 144

56 Planning the electrical installation
This table shows the minimum cross-sectional area related to the phase conductor size
according to IEC 61800-5-1 when the phase conductor and the protective conductor are
made of the same metal. If this is not so, the cross-sectional area of the protective earthing
conductor shall be determined in a manner which produces a conductance equivalent to
that which results from the application of this table.
Compared to a four-conductor system, the use of symmetrical shielded cable reduces
electromagnetic emission of the whole converter system as well as generator bearing
currents and wear.
The generator cable and its PE pigtail (twisted screen) should be kept as short as possible
in order to reduce electromagnetic emission as well as capacitive current.
Cross-sectional area of the phase conductors
S (mm
2
)
Minimum cross-sectional area of the
corresponding protective conductor
S
p
(mm
2
)
S < 16 S
16 < S < 35 16
35 < S < 400 S/2
400 < S < 800 200
800 < S S/4