RKL4531 by Bosch Rexroth Indramat

The RKL4531 is a flexible motor power cable manufactured by Bosch Rexroth Indramat as part of the RKL Motor Power Cables series. Designed for dynamic machine installations, the cable links an Indramat drive controller to its servo motor, delivering three-phase power while housing feedback and brake conductors in a single assembly. By consolidating these conductors, the product simplifies routing inside drag chains and supports synchronized motion sequences in industrial automation lines. Its construction is tuned for repetitive movement and electrical consistency over a long service life.

During operation, the cable is rated for 5 million flex cycles, which shows its suitability for repeated bending in moving applications. A nominal outside diameter of 30.8 mm helps with cable tray and gland sizing. The copper power cores each have a cross-section of 35.0 mm², allowing low voltage drop at the high currents typical of medium-frame servomotors. At 20 °C, the loop resistance is 0.554 ?/km, so a 10 m run introduces only 5.54 m? of series resistance, which helps limit thermal losses. Dielectric behavior is characterized by a specific capacitance of 1.2 nF/m, which the drive must account for when switching at high carrier frequencies to reduce excess reactive current.

The cable also integrates control cores with a section of 1.5 mm², making them suitable for a holding-brake supply or temperature sensors without a separate harness. A tough PUR outer jacket shields the bundle from oils and coolants, while its bright RAL 2003 (Orange) color helps distinguish it from signal wiring. For moving-chain layouts, the minimum dynamic bend radius is 7.5 × D, while fixed routing can use a tighter 5 × D bend without placing unnecessary stress on the insulation. This layout supports both moving and stationary cable runs in industrial equipment.