Product Description:

The RD51.1-4N-030-D-NN-FW is a drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It is intended for variable-speed operation of induction motors, adjusting output frequency and voltage to match process demands in automated lines, conveyors, and pump stations. By converting incoming three-phase line power into a regulated output, the unit links plant-level control signals with the mechanical work performed by the motor. This type of controller is commonly used where motor speed must follow changing load conditions without mechanical throttling. That makes it suitable for process equipment that needs repeatable speed adjustment during normal operation.

The controller supplies up to 30 kW of mechanical power and accepts line voltages from 380 to 480 V, allowing use on common industrial networks. Its input format is a 3 x AC converter input, so the drive rectifies and inverts a three-phase supply rather than relying on a single-phase source. Motor flux is regulated with U/f curve control, a scalar method that maintains a constant volts-per-hertz ratio for stable torque across the speed range. This control method is well suited to applications such as pumps and conveyors, where smooth speed regulation is more important than fast servo response. Thermal energy is removed through a plug-through cooler for ratings up to 110 kW, which places the heat sink outside the cabinet surface and helps reduce enclosure temperature.

Supply fluctuations are handled with a tolerance of ±10 %, so the drive can continue operating when the line voltage drifts within that band. The unit is supplied without a built-in brake chopper, so dynamic braking requires an external resistor or regenerative module when rapid deceleration is needed. This arrangement is appropriate for systems that use long deceleration ramps or do not depend on frequent high-energy braking. Line-side disturbances are attenuated by an integrated mains filter, which helps limit high-frequency emissions into the distribution system. The controller is part of Generation 1 of the platform.