RKL4320 by Bosch Rexroth Indramat

The RKL4320 cable is manufactured by Bosch Rexroth Indramat and belongs to the RKL Motor Power Cables series. It is used to distribute three-phase motor power together with brake or auxiliary signals between Rexroth drive controllers and synchronous servomotors in automated lines. The cable is intended for continuously moving cable-track installations, where repetitive flexing and torsion require a durable power link that maintains low leakage and stable impedance for precision motion control. Its combined power and auxiliary conductors also reduce the need for separate moving cable runs on compact axes. That arrangement keeps the power path and auxiliary wiring in one flexible assembly instead of splitting them into separate cable packages.

The mechanical life of the cable is rated for 5,000,000 bending cycles, indicating how many dynamic movements the conductors and insulation can withstand before fatigue becomes critical. A PUR jacket surrounds the core bundle, and this polyurethane sheath resists abrasion from cable trays, cutting fluids, and UV exposure. Electrical behavior includes a capacitance of 0.8 nF/m, which helps limit reactive current at high PWM switching frequencies. The 1.5 mm² copper conductors have a resistance of 13.3 ?/km, which helps reduce voltage drop over long runs. Four auxiliary cores are included as 4 × 0.75 mm² control conductors, so brake circuits or temperature sensors can be connected without a separate harness.

Dynamic installation constraints require a bending radius of 7.5 × D during motion, allowing tight routing inside cable chains without compressive kinking. The cable has a halogen-free design, so combustion products do not contain corrosive acids that could damage nearby electronics in the event of fire. Its insulation is rated for 300/500 V, matching the drive output of low-voltage servo systems. The cable has an outer diameter of 12.2 mm, which supports dense bundling inside energy-supply dress packs and leaves room for adjacent lines in crowded moving installations. The reduced diameter also helps the cable move more freely where chain space is limited and bend points are closely spaced.