Alternative Power Cable Types; Motor Cable Shield - ABB ACS150 series User Manual

Alternative power cable types

Power cable types that can be used with the drive are presented below.
Allowed as motor cables
(recommended for input cables also)
Symmetrical shielded cable: three phase conductors,
a concentric or otherwise symmetrically constructed
PE conductor and a shield
PE conductor
and shield
Allowed as input cables
A four-conductor system: three phase conductors and
a protective conductor
Not allowed for motor cabling: Separate cables for
each phase and 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
Shield
PE
PE
Copper wire screen
Note: A separate PE conductor is required if the
conductivity of the cable shield is not sufficient for the
purpose.
PE
Cable core
Planning the electrical installation
31
Shield
PE
Shield
PE