Cables - Salicru CV30 User Manual

C.3 Cables
C.3.1 Power cables
Dimension the input power and motor cables according to local regulations.
• The input power and the motor cables must be able to carry the corresponding load currents.
• The cable must be rated for at least 70 °C maximum permissible temperature of the conductor in
continuous use.
• The conductivity of the PE conductor must be equal to that of the phase conductor (same
cross-sectional area).
• Refer to chapter Technical Data for the EMC requirements.
A symmetrical shielded motor cable (see the figure below) must be used to meet the EMC requirements of the CE.
A four-conductor system is allowed for input cabling, but a shielded symmetrical cable is recommended.
Compared to a four-conductor system, the use of a symmetrical shielded cable reduces electromagnetic
emission of the whole drive system as well as motor bearing currents and wear.
Note: A separate PE conductor is required if the conductivity of the cable shield is not sufficient for the
purpose.
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 aluminum 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 is, the lower the emission level and bearing currents.
C.3.2 Control cables
All analog control cables and the cable used for the frequency input must be shielded. Use a double-shielded
twisted pair cable (Figure a) for analog signals. Employ one individually shielded pair for each signal. Do not
use common return for different analog signals.
Appendix C Peripheral Options and Parts 133 - 140