RKL4780 by Bosch Rexroth Indramat

The RKL4780 is a motor power cable produced by Bosch Rexroth Indramat within the RKL Motor Power Cables series. It serves as the primary energy path between an Indramat controller and its matched servo motor, carrying three large conductors for phase current plus separate signal pairs required for temperature or brake monitoring. The assembly supports continuous motion in drag-chain environments, giving machine builders a pre-terminated solution that simplifies wiring and maintains electromagnetic compatibility in automated cells.

The bulk conductor set follows the INK0667 geometry, and the outer sheath is molded from PUR to resist cutting oils and flex fatigue. The cable has a diameter of 30.8 mm and contains 8 cores, so power and control lines are housed in one run. Each power core provides a cross-sectional area of 35.0 mm², supporting the high currents drawn by large synchronous motors, while the control cores use a 1.5 mm² section suited to sensor loads. Line-to-line capacitance measures 1.2 nF/m, a value used when selecting output filters to keep dV/dt within insulation limits. Factory-installed plugs simplify field work: the controller end terminates with RLS0727/K35, and the motor end uses RLK1501, so no crimping or soldering is required during installation.

Mechanical life is rated for 5,000,000 flex cycles, a value matched to typical drag-chain service intervals. During motion, the jacket can bend repeatedly down to a dynamic radius of 7.5×D, while static installation can tighten to 5×D without kinking conductors. Copper pathways exhibit a resistance of 0.554 ohm/km at 20 °C, allowing voltage-drop calculations for extended runs. The cable is intended for high-duty robotic and conveyor axes that require repeated flexing and stable power delivery.