RKL4750 by Bosch Rexroth Indramat

The RKL4750 is a flexible motor power cable produced by Bosch Rexroth Indramat within the RKL Motor Power Cables series. It forms the energy link between Indramat drive controllers and servo motors, carrying three-phase power and auxiliary control signals through pre-assembled connectors so moving axes can be installed quickly in automated machinery. The cable is designed for continuous motion in cable chains and robot arms, allowing reliable transmission of drive current and control signals in demanding industrial automation environments.

The cable is rated for 5,000,000 bending cycles, so it is suited for repeated flexing in moving applications. During motion, the conductors can be bent down to a minimum dynamic loop of 7.5 × D, whereas stationary installation permits a tighter static loop of 5 × D; these limits help size carrier trays and service loops. An overall diameter of 30.8 mm results from four power cores, a protective earth bundle, and four shielded control leads. Each power core is 35.0 mm² to keep voltage drop low on long runs, while a conductor resistance of 0.554 ?/km shows the copper loss that should be considered in thermal calculations. Additional 1.5 mm² control pairs carry brake release or temperature signals without sharing the power bundle.

In applications involving fast acceleration, electrical performance also depends on distributed cable parameters. The cable exhibits a capacitance of 1.2 nF/m, which affects drive output filters and the switching frequency that pulse-width-modulated inverters can support. Its power cores are insulated for 300/500 V operation, while the four control cores are limited to 300 V. The controller side uses the factory-molded RLS0723 (K35) connector, which mates directly with the cabinet bulkhead, and the opposite end carries an RLK1401 plug for direct motor connection.