Product Description:

The RS51.1-4G-031-L-NN-FW is a basic drive from Bosch Rexroth Indramat in the RD 500 Drive Controllers series. As a line-supply converter, it interfaces between a three-phase mains network and induction motors, providing regulated voltage and frequency so that speed and torque can match process demands in automated machinery such as conveyors, pumps, and assembly stations. It is intended for variable-speed applications that need dependable motor control in a standard drive configuration.

Its continuous output is rated at 31 kVA, allowing the module to supply medium-frame motors without derating under normal operating conditions. The converter accepts an input line from 380 to 480 V AC and remains stable across fluctuations within ±10 % of that range, which supports use on industrial feeders with moderate voltage variation. Motor excitation is handled with U/f curve control, where frequency is adjusted in proportion to stator voltage so the drive can maintain constant flux and avoid saturation at low speeds. Power is supplied through a three-phase AC converter arrangement, so the unit rectifies the incoming mains power and reconstructs a variable-frequency output waveform for the motor. This operating method supports both steady-state running and acceleration during changing load conditions.

Thermal management relies on forced-air cooling, with internal airflow moving across the heat sink to keep semiconductor temperatures within their operating limit. A built-in brake chopper and resistor dissipates regenerated energy during deceleration, which helps prevent DC-bus overvoltage when the motor is slowing a load. Input harmonics are reduced by the integrated mains filter, reducing the need for separate external filtering components in many cabinet layouts. The unit is part of Design generation 1. Its control board is delivered without optional function modules, so the base unit is limited to the standard features included with this drive.