1.2 Cable ductsa. Power and signal

1.2 Cable ductsa. Power and signal cables (motor cables, cables leading from frequency inverters to measuring lines, or BUS cables, etc.) must be laid in separate ducts, or ducts with separators must be used.b. Cable ducts between the control cabinet and the installation must be metallic. Exceptions are possible in chemical plants.c. Cable ducts must be consistently provided with low-resistance earth connections (via mechanical screwed connections). In special cases, for large plants or systems, technical agreements must be made between the manufacturer and operator, clarifying in which way the earth connection can be established. An existing protective earth connection must be integrated into the PE conductor system.1.3 Installationa. The use of electrical components (in particular motor cables) requires compliance with manufacturers’ installation specifications.b. Cables are to be run as close and extensively as possible to surfaces connected to earth.c. Wound up cable harnesses are to be avoided.d. For the earth equalizing conductor, use a cross-section as big as possible between the cabinet and the machine ( ≥ 16 mm2 ). If the use of additional earth equalizing conductors is required, cross-sections ≥ 6 mm2 must be used.e. If possible, lay power and signal cables separately.f. Connect the cable shield to earth creating a large surface connection (clamp to earthing bar).1.4 Current distributionCurrent distribution is implemented using compact busbar systems / components. Products by Rittal and Wöhner are to be preferred.The type series used are to be specified in the offer.When DO1/DO2 fuses are used, fuse switch-disconnectors have to be provided.The design of the supply cable connection generally has to be clarified with the corresponding department.