RKL4571 by Bosch Rexroth Indramat

The RKL4571 is a motor power cable manufactured by Bosch Rexroth Indramat for the RKL Motor Power Cables series. It is intended for industrial automation tasks that require reliable transmission of drive voltage and control signals between a servo amplifier and a moving motor. By combining power cores with paired control leads in a single PUR-jacketed assembly, it streamlines wiring inside cable tracks and reduces the space needed for routed cable bundles. This layout also reduces the number of separate cable runs that must move with the axis, which helps keep routing orderly in compact machine frames.

The overall outer diameter is 25.5 mm, so bulkhead fittings and drag-chain partitions must accommodate that cross-section. A conductor resistance of 1.21 ?/km characterizes copper losses at 20 °C and helps determine practical cable length under load. The three power conductors use a 16.0 mm² cross-section, supporting phase currents associated with drives that operate up to 600 V AC. Two shielded signal pairs with a conductor layout of 2x(2x1.5 mm²) carry brake or temperature-sensor lines while remaining inside the same outer sheath. Their shielding helps reduce interference from the switching of the motor phases, and auxiliary circuits in the machine operate at 300 V, which stays below the insulation limit of the control pair.

The cable withstands 5,000,000 flex cycles in energy chains, enabled by a PUR jacket that resists abrasion and oil exposure while remaining halogen-free to reduce smoke toxicity. Continuous movement is possible because the dynamic bend radius is 7.5 × D, whereas stationary runs may be laid at 5 × D without added mechanical strain. Horizontal track lengths can extend to 50 m, which suits long-travel gantry axes and other moving machine sections. During operation, conductor temperature may rise to 90 °C without damaging insulation when the applied load and surrounding conditions remain within the allowed operating range. The jacket material also supports repeated movement through guides and carriers where rubbing and flexing occur throughout normal machine cycles.