Selecting The Power Cables; General Rules; Power Cable Shield - ABB ACSM1 Hardware Manual

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Selecting the power cables

General rules

Dimension the power cables according to local regulations.
• The cable must be able to carry the regen supply module load current. See the
chapter
• The cable must be rated for at least 70
permissible temperature of conductor in continuous use.
• The conductivity of the PE conductor must be equal to that of a phase conductor
(ie. same cross-sectional area). See also
• 600 VAC cable is accepted for up to 500 VAC.
• Refer to the chapter
A four-conductor system is allowed for input cabling, but shielded symmetrical cable
is recommended. Compared to a four-conductor system, the use of symmetrical
shielded cable reduces electromagnetic emission of the whole drive system.

Power cable shield

To function as a protective conductor, the shield must have the same cross-sectional
area as a phase conductor 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. An example 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, the lower the emission level and the bearing
currents.
Planning the electrical installation
Technical data for the rated currents.
Technical data
Copper wire screen
Insulation jacket
°
C (US: 75 °C [167 °F]) maximum
Supply connection
for EMC requirements.
Helix of copper tape
on page 39.
Inner insulation
Cable core