RKL4491 by Bosch Rexroth Indramat

The RKL4491 is a motor power cable engineered by Bosch Rexroth Indramat and supplied within the RKL Motor Power Cables series. Designed as the electrical link between an IndraDrive controller and a synchronous servo motor, it carries three-phase power and auxiliary control conductors while tolerating constant motion in automated machinery. The combined power and auxiliary conductors help reduce the number of separate cables routed to the motor. Within an installation, the cable's construction protects against electrical losses and mechanical fatigue so that moving axes receive consistent current without unplanned downtime.

Its copper conductors present a resistance of 0.554 ohm/km, a value that limits I²R losses over long cable runs and keeps drive efficiency stable. The three main power cores employ a cross-section of 35.0 mm², allowing high rms current flow that matches servo drives in the 40 kW range while controlling temperature rise inside the sheath. For insulation coordination, the cable is rated for 600 V AC, so it can be wired directly to standard low-voltage industrial switchgear. A molded outer diameter of 30.8 mm simplifies routing through drag chains and flexible trays, and the external sheath is made from PUR (adhesion-free, matte), a thermoplastic polyurethane that resists oil, weld spatter, and abrasion. One end terminates in an RLS0723 (K35) bayonet connector for the drive, while the motor side is supplied with ferrules and a ring terminal set to simplify field assembly.

Inside the jacket, a separate pair for brake or sensor supply uses a cross-section of 1.5 mm², providing enough conductor area for auxiliary currents without adding stiffness. The cable tolerates motion cycles with a dynamic bend radius of 7.5 × D, while stationary installations may be laid at a tighter static radius of 5 × D; these limits help prevent micro-cracking of insulation when the line is reeled or clamped. Service temperature spans -20 to +40 °C, covering most cabinet and machine environments found in automated transfer lines and palletizing gantries.