Guidelines for planning the electrical installation 57 Alternative power cable typesThe recommended and not allowed power cable types to be used with the drive arepresented below.Recommended power cable typesPower cable types for restricted useNot allowed power cable types Motor cable shieldIf the motor cable shield is used as the sole protective earth conductor of the motor, makesure that the conductivity of the shield is sufficient. See subsection General rules above, orIEC 61439-1. To effectively suppress radiated and conducted radio-frequency emissions,the cable 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 minimumrequirement of the motor cable shield of the drive is shown below. It consists of aconcentric layer of copper wires with an open helix of copper tape or copper wire. Thebetter and tighter the shield, the lower the emission level and bearing currents.Symmetrical shielded cable with three phase conductors and a concentric PEconductor as shield. The shield must agree with the requirements ofIEC 61439-1, see section Motor cable shield on page 57. Check with local /state / country electrical codes for allowance.Symmetrical shielded cable with three phase conductors and a concentric PEconductor as shield. A separate PE conductor is required if the shield does notagree with the requirements of IEC 61439-1, see section Motor cable shield onpage 57.Symmetrical shielded cable with three phase conductors and symmetricallyconstructed PE conductor, and a shield. The PE conductor must agree with therequirements of IEC 61439-1, see section Motor cable shield on page 57.A four-conductor system (three phase conductors and a protective conductor ona cable tray) is not allowed for motor cabling (allowed for input cabling).Symmetrical shielded cable with individual shields for each phase conductor isnot allowed on any cable size for input and motor cabling.PEPEPEPEPE
