RKL4554 by Bosch Rexroth Indramat

The RKL4554 is a motor power cable produced by Bosch Rexroth Indramat within the RKL Motor Power Cables series. It connects variable-frequency drives to synchronous or asynchronous motors, transmitting three-phase power with auxiliary conductors for brake release and sensor supply. In automated machinery, the cable acts as a flexible link that moves inside drag chains while delivering both energy and control signals.

The cable core contains three power conductors, each with a cross-section of 4.0 mm², allowing continuous current transfer while limiting heating under the rated line voltage of 300/500 V. The overall outside diameter is 17.0 mm, so routing space inside energy chains can be planned precisely. The dielectric between the spiral-layered cores creates a mutual capacitance of 0.8 nF/m, and low capacitance helps minimize reactive current drawn by PWM inverters. Direct-current losses are limited by a conductor resistance of 4.95 ?/km, which helps verify voltage drop over long machine axes. A matte PUR outer sheath resists oils and welding sparks, and its orange RAL 2003 color follows common machine-safety coding. The cable is suitable for continuous motion in drag chains, so cycle counts in the millions are achievable.

In addition to the three main phases and protective ground, the design integrates 2×1.0 mm² + 2×1.5 mm² auxiliary pairs for brake coils, temperature sensors, or feedback power, bringing the assembly to 8 insulated conductors. These auxiliaries operate on control circuits up to 300 V, matching common 24-230 V interface levels with ample margin. For dynamic routing, the flexible bend radius is limited to 7.5×D. Following this limit helps avoid corkscrewing and prolong insulation life during acceleration and torsion. When clamped in stationary trays, the radius requirement relaxes to 5×D, easing cabinet entry transitions.