RKL4578 by Bosch Rexroth Indramat

The RKL4578 is a flexible motor power cable manufactured by Bosch Rexroth Indramat within the RKL Motor Power Cables series. It carries drive output power and paired control conductors from cabinet-mounted inverters to moving servo motors or spindles in industrial automation cells. Proper conductor sizing, electromagnetic shielding, and mechanical durability help the assembly maintain stable power transfer while the connected axis follows repeated motion paths. It can be routed between a stationary control cabinet and a moving machine axis without separating the power and auxiliary conductors into different cable runs.

Its copper power cores have a cross-section of 16.0 mm², giving a continuous current capacity of 71.3 A at 40 °C so medium-frame synchronous motors can start and run without excessive voltage drop. Two paired control loops, each 1.5 mm², are integrated for temperature sensors or brakes, which reduces the need for separate auxiliary wiring. The polyurethane jacket has an outside diameter of 25.5 mm, so it fits standard cable trays while resisting abrasion in moving installations. Conductor insulation withstands up to 80 °C during sustained loading, and the PUR jacket resists oil and coolant exposure. For stationary routing, the cable may be bent down to a radius of 5 × D, and it is rated for 5,000,000 dynamic bending cycles in drag-chain service. These features support reliable use on axes that cycle continuously through short and repeated travel patterns.

For moving axes, the minimum bend radius is 7.5 × D, which helps determine cable-chain pitch and compartment spacing. The assembly uses a standard metric gland with an M40 × 1.5 thread to provide strain relief and sealing at the motor housing. A Total Shield made with braid and foil limits common-mode noise and supports compliant EMC layouts near drive electronics. The outer jacket is Orange (RAL 2003), making the cable easy to identify during visual checks on the factory floor. Shield coverage and jacket toughness are especially useful where power conductors and auxiliary wiring run close to one another in compact machine sections.