ABB ACS850-04 series, Руководство по оборудованию

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Planning the electrical installation
58
Alternative power cable types
The power cable types that can be used with the drive are represented below.
Motor cable shield
If the motor cable shield is used as the sole protective earth conductor of the motor,
ensure that the conductivity of the shield is sufficient. See subsection
General rules
above, or IEC 60439-1. To effectively suppress radiated and conducted radio-
frequency emissions, the shield conductivity must be at least 1/10 of the phase
conductor conductivity. The requirements are easily met with a copper or aluminium
shield. The minimum requirement of the motor cable shield of the drive is shown
below. It consists of a concentric layer of copper wires with an open helix of copper
tape or copper wire. The better and tighter the shield, the lower the emission level
and bearing currents.
Recommended: Symmetrical shielded cable: three phase conductors and a concentric or
otherwise symmetrically constructed PE conductor, and a shield
PE conductor
and shield
Shield
Shield
Note: A separate PE conductor is
required if the conductivity of the
cable shield is < 50 % of the
conductivity of the phase
conductor.
PE
PE
Shield
PE
Not allowed for motor cabling : A four-conductor system (three phase conductors and a
protective conductor)
Not allowed for input or motor cabling: Symmetrical cable with individual shields for each phase
conductor
Shield
PE