Chapter 3 – Electrical Installation
ACS/ACC/ACP 601 Frequency Converters 3-3
Alternative Power Cable
Types
Power cable types that can be used with ACx 600 are represented
below.
Motor Cable Shield
To effectively supress radiated and conducted radio-frequency
emissions, the shield conductivity must be at least 1/10 of the phase
conductor conductivity. One way of evaluating the effectiveness of the
shield is the shield inductance, which must be low and only slightly
dependent on the frequency. These requirements are easily met with a
copper or aluminium shield/armour. The minimum requirement of the
motor cable shield of the ACx 600 is shown below. It consists of a
concentric layer of copper wires with an open helix of copper tape. The
better and tighter the shield is, the lower is the emission level and the
bearing currents.
Symmetrical shielded cable: three phase conductors
and a concentric or otherwise symmetrically
constructed PE conductor, and a shield
Recommended
PE conductor
and shield
Shield
Shield
A separate PE conductor is required if the conductivity
of the cable shield is < 50 % of the conductivity of the
phase conductor.
A four-conductor system:
three phase conductors
and a protective
conductor.
Shield
PE
PE
PE
Not allowed for motor cables with phase
conductor cross section larger than 10 mm
2
(motors > 30 kW).
Not allowed for motor cables
Insulation jacket
Copper wire screen
Helix of copper tape
Cable core
Inner insulation
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