Alternative power cable types
Power cable types that can be used with the drive are presented below.
Allowed as motor cab
l
es
(recommended for input cables also)
Symmetrical shielded cable: three phase conductors,
a concentric or otherwise symmetrically constructed
PE conductor and a shield
Note: A separate PE conductor is required if the
conductivity of the cable shield is not sufficient for the
purpose.
PE conductor
and shield
Shield
Shield
PE
Allowed as input cables
A four-conductor system: three phase conductors and
a protective conductor
PE
Shield
PE PE
Not allowed for motor cabling: Separate cables for
each phase and PE
PE
Motor cable shield
To function as a protective conductor, the shield must have the same cross-sectional
area as the phase conductors when they are made of the same metal.
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. The better and tighter the shield, the lower the
emission level and bearing currents.
Insulation jacket
Copper wire screen
Cable core
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