RKL4420 by Bosch Rexroth Indramat

The RKL4420 belongs to the RKL Motor Power Cables series produced by Bosch Rexroth Indramat. It is a shielded motor-supply cable intended for servo drives and variable-frequency inverters in automated machinery. By combining power conductors and low-voltage control pairs inside a single PUR sheath, the cable simplifies routing between the cabinet and a moving axis while maintaining signal integrity during continuous motion. Its combined layout also reduces the need for separate auxiliary cabling on axes that require both motor power and secondary control connections.

The cable is rated for 5 million bending cycles, making it suitable for installations where it flexes during each machine cycle. When mounted in energy-chain carriers, it can bend to a minimum dynamic radius of 7.5 × D without damaging the copper strands or insulation. Power losses over distance are limited by a conductor resistance of 1.21 ?/km, and the three-phase supply is carried through a 4×16.0 mm² litz construction that supports high motor currents. The circular sheath diameter of 25.5 mm determines the required gland and chain channel size. The cable is suitable for drag-chain service, so it withstands repeated acceleration, abrasion, and vibration without insulation cracks or jacket swelling.

For static sections, the minimum bend radius is 5 × D, and integrated signal cores arranged as 2×(2×1.5 mm²)+2×(1.0 mm²) support temperature monitoring or brake control without a separate harness. The insulation system is PUR, which provides cut resistance and oil tolerance, while the outer jacket is color coded RAL 2003 for quick identification in mixed cable trays. Because the sheath is halogen-free, it does not release corrosive gases during a fire, which supports safety in enclosed factory spaces. A low discharge capacitance of 1.2 nF/m limits capacitive loading on the drive output, and the finely stranded copper conductors help preserve flexibility through both moving and fixed cable runs.