RKL4755 by Bosch Rexroth Indramat

The RKL4755 cable is a preassembled motor power lead produced by Bosch Rexroth Indramat for machines that use the RKL Motor Power Cables series. As part of a drive system, this cable routes three-phase supply and auxiliary control signals between the inverter and the motor, allowing servo axes to receive power through one organized cable assembly. Its design supports the continuous motion found in gantries, pick-and-place modules, and other dynamic automation equipment where repeated flexing is common.

Four copper cores are dedicated to the motor phases, giving the assembly 4 power conductors each sized at 4.0 mm² so current can be carried without oversizing the cable. Next to them, the cable houses four auxiliary lines; two of these use a conductor size of 1.0 mm², while the remaining pair use 1.5 mm² to support brake release or temperature-monitoring loads. Mechanical life is rated for 5,000,000 bending cycles, indicating how many reciprocating flexes the sheath, fillers, and conductor strands can withstand before insulation damage becomes likely. The separate auxiliary group also helps keep low-level control functions apart from the power bundle during repetitive motion.

When laid in a fixed installation, the sheath may be bent to a radius of 5 × D. In continuously moving cable chains, the minimum radius increases to 7.5 × D so copper strand fatigue is less likely during long travel. The operating temperature range also changes with installation style: fixed runs can operate from -30 to +40 °C, while traveling runs are limited to -20 to +40 °C because jacket flexibility decreases in colder conditions. Internal conductor insulation can handle higher conductor temperatures during operation, and the stated storage range helps keep the jacket stable during transport and warehousing before the cable is put into service.