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Planning the electrical installation 55
To avoid damage to generator bearings, the cables must be selected and installed
according to the instructions given in this manual. In addition, insulated N-end (non-
converter end) bearings must be used.
Selecting the power cables
General rules
Dimension the grid cable or busbar and generator cable
according to local regulations
:
•
The cable must be able to carry the converter load current. See chapter
on page
for the rated currents.
•
The cable must be rated for at least 90 °C (194 °F) maximum permissible temperature
of conductor in continuous use. See also section
on page
.
•
The inductance and impedance of the PE conductor/cable (grounding wire) must be
rated according to permissible touch voltage appearing under fault conditions (so that
the fault point voltage will not rise excessively when a ground fault occurs).
•
The rated voltage between the conductors of the cable should be minimum 1 kV.
For generators, the symmetrical shielded generator cable is highly recommended. See
section
on page
Note:
When continuous conduit is employed, shielded cable is not required.
Note:
When using a four-conductor system, consult the generator manufacturer regarding
bearing and disturbance shielding.
In a non-symmetrical four-conductor system, voltage can be induced to the separate PE
conductor, which rises generator frame potential and causes current to ground through the
generator bearings and shaft. This causes extra wear. Whereas, in a symmetrical shielded
cable, the high capacitance between the PE conductor and the phase conductors forms an
LC filter reducing bearing currents and voltage changes.
A four-conductor system is allowed for grid cabling, but shielded symmetrical cable is
highly recommended.
Sufficient conductivity of the protective conductor
The protective conductor must always have an adequate conductivity.
Unless local wiring regulations state otherwise, the cross-sectional area of the protective
conductor must agree with the conditions that require automatic disconnection of the
supply required in 411.3.2. of IEC 60364-4-41:2005 and be capable of withstanding the
prospective fault current during the disconnection time of the protective device.
The cross-sectional area of the protective conductor can either be selected from the table
below or calculated according to 543.1 of IEC 60364-5-54.
Summary of Contents for ACS880-87LC-4000A/4021A-7
Page 4: ......
Page 10: ...10 ...
Page 17: ...Safety instructions 17 1 3 2 4 5 6 7 ...
Page 18: ...18 Safety instructions 8 9 ...
Page 28: ...28 Introduction to the manual ...
Page 52: ...52 Mechanical installation ...
Page 66: ...66 Planning the electrical installation ...
Page 74: ...74 Electrical installation Diagrams for the customer connections are presented below ...
Page 75: ...Electrical installation 75 optional Fast shutdown ...
Page 85: ...Maintenance 85 b c a Air flow direction 2 3 4 6 ...
Page 87: ...Maintenance 87 2 5 4 ...
Page 88: ...88 Maintenance 7 Arrow indicating the air flow direction 5 6 6 ...
Page 90: ...90 Maintenance Air flow circulation b a ...
Page 106: ...106 Maintenance ...
Page 124: ...124 Control units of the converter ...
Page 126: ...126 Dimension drawings ...
Page 127: ...Dimension drawings 127 ...
Page 128: ...128 Dimension drawings ...
Page 142: ...142 Cooling and heating ...