RL2-521CBB by Bosch Rexroth Indramat

The RL2-521CBB cable is a motor power lead produced by Bosch Rexroth Indramat within the RL2 Motor Power Cables series. Designed for second-generation servo assemblies, it links drive amplifiers to rotary or linear motors while carrying mains power and auxiliary lines used for closed-loop control in automated machinery. That combined layout lets one cable handle motor power and supporting circuit connections instead of splitting those functions across separate runs. It follows standard color coding and shielding practices so power and signal conductors can be routed together without creating unnecessary electromagnetic interference.

The cable includes four 0.75 mm² auxiliary conductors for encoder supply or brake release signals. Inside a basic PVC jacket, it has an outer diameter of 12.0 mm, allowing compact routing through drag chains where space is limited. Power delivery is carried by 4 primary cores, each with a cross-section of 1.0 mm², for servo axes that draw continuous current during normal operation. The round profile helps keep the cable stable in motion, and its leakage capacitance is 0.4 nF/m, which supports consistent switching behavior at the drive output. Electrical insulation is rated to 600/1000 V for the power paths and 450/750 V for the auxiliary conductors. The auxiliary conductors are intended for low-power control-related functions that travel with the motor lead.

For flexible installation, the cable can be laid statically with a minimum bend radius of 5 × D or used in cable carriers down to 7.5 × D. During motion, it also tolerates torsional twisting of ±30° per meter, which is useful where machine axes introduce repeated cable rotation. The cable remains suitable for moving applications down to -20 °C, and fixed installations may reach +80 °C without jacket degradation. Fixed routing can also be used at temperatures as low as -30 °C, while the dynamic upper limit is +60 °C during continuous service.