RKL4739 by Bosch Rexroth Indramat

The RKL4739 motor power cable is produced by Bosch Rexroth Indramat and belongs to the RKL Motor Power Cables series. Designed for fixed installation between an IndraDrive controller and a terminal-box-style motor, the assembly carries three-phase power along with dedicated control pairs, allowing coordinated torque and brake circuits inside automated machinery. Its purpose in industrial automation is to deliver regulated line voltage and auxiliary signals from the drive cabinet to the machine actuator while maintaining flexibility and resistance to common industrial chemicals. Because it is intended for stationary routing, the cable is suited to secured runs along machine frames, panels, or protected cable channels. This layout also helps keep cabinet-to-motor wiring organized where separate brake and thermal leads are required.

Four copper conductors with a cross-section of 50.0 mm² form the main power path, matching drives that supply up to 4 A per square millimeter without excessive heating; this sizing supports the cable's rated line voltage of 600 V AC. DC resistance at 20 °C is limited to 0.386 ?/km, so voltage drop stays low on lengths typical for multi-axis cells. The circular composite sheath measures 36.8 mm in outer diameter and encloses the 4×50.0 mm² power cores plus two twin control pairs, as shown by the 4×50.0 mm² + 2×(2×2.5 mm²)StC cable layout. A bright RAL 2003 orange jacket aids route identification, and variant K50 lugs simplify attachment to the controller housing. The large conductor area also helps reduce resistive losses on longer machine runs where stable motor current delivery is important.

The auxiliary pairs each use a cross-section of 2.5 mm², and they are insulated for a control voltage limit of 300 V, so brake release or thermal sensor circuits can share the same harness. The cable has a capacitance of 1.3 nF/m, which affects high-frequency behavior between the drive and the motor. The matte, adhesion-free PUR outer jacket resists cutting oils and supports continuous flexing. At the terminal-box end, eight conductors are pre-stripped, which helps separate power and control leads under screw clamps without extra cable preparation.