RKL4339 by Bosch Rexroth Indramat

The RKL4339 motor power cable is produced by Bosch Rexroth Indramat within the RKL Motor Power Cables series. This molded assembly bridges servo drives and synchronous motors by carrying three-phase power plus brake control signals in a single flexible line, streamlining machine wiring in automated cells and gantry axes. Designed for moving-axis routing inside cable chains, the cable maintains electrical integrity under repetitive bending, and its factory-installed connectors simplify installation. It is used where standard stationary leads would fail from motion, allowing predictable motor current delivery and reliable brake actuation.

Mechanically, the cable is rated for 5,000,000 flex cycles, supporting long-life operation in high-duty drag-chain paths. Flexibility is aided by a dynamic minimum bend radius of 7.5 × D, so the allowed arc can be calculated from the actual outer diameter. Electrically, the line accommodates drive outputs up to 600 V AC under UL listing, and the distributed conductor geometry yields a capacitance of 1.0 nF/m, a modest value that helps limit reactive current in high-frequency pulse-width-modulated drives. The motor side uses connector RLS1302/C10, while the drive end is fitted with RLS1301/C10. A matte PUR jacket resists oil and weld spatter, and the bulk cable designation is INK0605.

Once installed, static routing zones require a minimum bend radius of 5 × D, which supports compact cabinet entry without overstressing the core. The overall diameter is 22.2 mm, which permits clamping with standard metric strain-relief fittings. The main power bundle contains 4 x 10.0 mm² conductors, while brake feedback is carried by 2 x 1.0 mm² + 2 x 1.5 mm² auxiliary conductors. At 20 °C, the loop resistance is 1.91 ?/km, which helps estimate voltage drop across long articulating axes.