RKL4756 by Bosch Rexroth Indramat

The RKL4756 is a flexible motor power cable produced by Bosch Rexroth Indramat within the RKL Motor Power Cables series. It serves as the main supply link between an Indramat drive and its synchronous motor, combining three-phase power conductors with control and auxiliary cores in a single jacket. By supplying regulated current and transmitting status signals through matched wire pairs, the assembly simplifies routing in gantries, packaging machines, and other motion axes that demand predictable electromagnetic behavior.

The power circuit is carried by three conductors with a cross-section of 6.0 mm², sized to keep voltage drop low over standard machine lengths. In the same sheath, an auxiliary pair rated at 1.5 mm² feeds brake release or fan functions, while a separate control pair of 1.0 mm² supports temperature or standstill monitoring. When energized, the copper bundle presents a loop resistance of 3.30 ?/km, a value used when calculating permissible cable runs and drive overload limits. Between the conductors and shield, the cable has a mutual capacitance of 0.8 nF/m, which must be considered when tuning output filters to suppress common-mode noise. All cores are insulated and covered with PUR, a jacket material chosen for oil resistance and high flex life in drag chains.

With an outer diameter of 18.5 mm, the cable fits standard metric cable glands and bends smoothly within the minimum trough radius used in automated handling systems. Continuous installation in fixed routing can tolerate conductor temperatures up to +90 °C, while dynamic applications are limited to a maximum core temperature of +80 °C to protect insulation integrity. Factory-installed connectors speed assembly: the drive end features the circular plug type RLS1202/C06, and the motor end uses the angled coupling RLK1201. A high-visibility RAL 2003 orange outer jacket helps identify motor lines among control bundles without opening trays.