MDC3.30B/SSA-1/S031

The Bosch Rexroth Indramat MDC3.30B/SSA-1/S031 is a permanent-magnet DC motor in the MDC DC Motors series. It supplies controllable shaft torque for industrial axes where closed-loop drives need fast current response and stable speed. A totally enclosed, nonventilated housing allows installation inside process machines without forced airflow or exposure to particles. Paired with a compatible DC controller, the motor accelerates conveyors, unwinders, or actuator screws using its low electrical time constants and high peak-current capacity. Operation is permitted at ambient temperatures up to 45 °C.

The electrical section draws a nominal armature current of 33 A to maintain continuous torque under the rated temperature rise. Each ampere delivers torque according to a constant of 0.80 Nm/A, so linear scaling between drive current and mechanical output simplifies controller tuning. A low armature resistance of 0.15 ohm limits copper loss at a steady load, while the 0.50 mH inductance sets the current-ripple bandwidth that the drive must manage. During steady operation, the generated back electromotive force is proportional to speed through a constant of 84 V/KRPM; this relationship allows speed feedback to be inferred from terminal voltage in open-loop modes. The built-in tacho generator has an armature resistance of 60 ohms and produces 33 V per 1,000 rpm. It operates with a 15-kilohm load and limits ripple to 0.5 percent, supplying stable velocity feedback.

Short-duty surges can be handled with a peak armature current of 300 A, giving the shaft additional starting torque beyond the continuous rating. The mechanical torque available for long duty cycles reaches 26 Nm. Thermal saturation is delayed by the motor’s large mass, which provides a winding thermal time constant of 220 min. This extended thermal response allows the windings to absorb temporary load changes without an immediate rise to their steady-state temperature. The controller must also respect a maximum commutator voltage of 170 V to remain within the motor’s insulation limits.