RKL4757 by Bosch Rexroth Indramat

The RKL4757 is a motor power cable manufactured by Bosch Rexroth Indramat for the RKL Motor Power Cables series. It supplies three-phase energy and auxiliary signals between drive controllers and servomotors in industrial automation cells, while its polyurethane outer sheath resists oils and coolant splashes commonly encountered around machine tools. By combining four dedicated power conductors with paired control cores inside a single jacket, the product simplifies routing in cabinets and cable tracks where space is limited and electromagnetic compatibility must be maintained.

The copper conductors present a resistance of 1.91 ?/km, so voltage drop remains low over typical motor lead lengths. For phase power, the cable contains 4×10.0 mm² cores that carry continuous motor current without excessive heating. Its mutual capacitance is limited to 1.0 nF/m, which helps the drive deliver clean PWM edges and reduces reactive current in high-frequency switching. A circular sheath diameter of 22.2 mm streamlines installation through standard cable glands, and the PUR jacket withstands mechanical abrasion while maintaining flexibility in dynamic drag-chain operation. The material formulation is halogen-free, so combustion gases remain low in corrosive elements and equipment in adjacent enclosures is protected during a fire event.

Two 1.0 mm² cores and two 1.5 mm² cores are available for motor temperature sensors or holding-brake supply, keeping feedback wiring inside the same protective hose. The conductors tolerate a continuous temperature of 90 °C when clamped in fixed runs and up to 80 °C in constantly moving applications, supporting mixed-duty cycles near hot motors. Cabinet layouts can maintain tight bends; static installation requires only a 111 mm radius, while mobile energy chains need a minimum of 166.5 mm to avoid copper strand fatigue. This arrangement keeps the cable bundle compact near the motor connection.