Product Description:

The RS51.1-4G-031-L-V1-FW/S117 is a basic drive controller produced by Bosch Rexroth Indramat within the RD 500 Drive Controllers series. It serves as the central power stage between a three-phase mains supply and an AC motor, converting line voltage into a regulated output that follows a selectable frequency profile. In automated machinery, the unit delivers the adjustable speed and torque needed for conveyors, pumps, and material-handling axes. It is suited for variable-speed applications that need stable motor control from a compact drive platform.

This controller is rated for 31 kVA of apparent power. This capacity indicates the maximum motor size and mechanical load it can support without derating. It accepts a line window of 380 to 480 V and maintains stable operation inside a tolerance band of ±10 %, allowing connection to industrial distribution systems that experience moderate voltage fluctuations. The supply interface uses a Converter 3 x AC arrangement, which rectifies and inverts three-phase mains into a variable-frequency output for the motor. Motor flux is regulated by U/f curve control, an open-loop method that keeps the ratio between voltage and frequency constant so induction motors can maintain consistent torque through much of the speed range.

Energy generated during rapid deceleration is absorbed by the drive's built-in brake chopper and resistor, preventing DC-bus overvoltage without extra external hardware. Thermal management relies on forced air cooling, so installation space must allow unobstructed airflow through the heat sink channels. A line-side filter is already integrated, which helps reduce conducted emissions and simplifies cabinet wiring. Control electronics can remain powered when the mains is off because the drive accepts an external 24 V standby power source, allowing communication and parameter access to stay available when the main power section is shut down. The device belongs to design generation 1 and is intended for applications that require adjustable motor speed and controlled torque delivery.