Product Description:

The RD52.1-4B-018-L-V1-FW/S136 is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. It converts three-phase input power into a regulated output for AC motors and uses vector-based regulation to maintain commanded speed and torque as load conditions change. In automated equipment, this allows the drive to support smoother acceleration, steadier low-speed operation, and reduced mechanical shock on connected machine elements.

This model has a continuous output rating of 18.5 kW, placing it in a power class suited to medium-duty motor applications. The supply stage uses a 3 × AC converter input, so the unit rectifies and inverts three-phase line power internally rather than depending on a separate DC supply section. It accepts input voltages from 380 to 480 V, and the allowable line variation of ±10% helps it remain stable when plant voltage shifts within normal industrial limits. Motion control is handled by field-oriented vector control, which separates torque and magnetic flux components so the motor can respond quickly during speed changes and hold steadier output at low speed.

Thermal management relies on forced air cooling, with cabinet airflow moving across the heatsink to remove switching and conduction losses from the power section. During deceleration, the built-in brake chopper routes regenerated energy to an external resistor so the DC link does not rise too high when the motor returns energy to the drive. An integrated mains filter reduces conducted electrical noise on the incoming supply, which helps the unit operate more cleanly in shared industrial power systems. The control section also supports 24 V standby power from an external source, allowing control electronics to remain active when the main input is isolated. The unit belongs to design generation 1.