Product Description:

The RD51.1-4B-075-L-V1-FW is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. It is intended to modulate the power delivered from a three-phase supply to an induction motor so that speed and torque can be matched to process demands in automated machinery, conveyors, and pumps. Internal control functions let the unit adapt operating behavior to load inertia, acceleration ramps, and incoming line conditions while maintaining stable motor response during routine speed changes.

This controller connects to a three-phase input of 380 to 480 V, and the internal power stage maintains performance within a line fluctuation of ±10%. The power section is sized for a continuous mechanical output of 75 kW, which suits medium-to-large motion axes or multi-motor groups on a common DC bus. As a 3 × AC converter, it rectifies and inverts line power rather than relying on an external transformer, which helps reduce panel space. Motor flux is regulated by U/f curve control, which keeps the voltage-to-frequency ratio constant so torque remains available across the speed range during normal operation.

Thermal management is handled by forced air cooling, and the heat sink channel is sized to remove losses from the power semiconductors at full current. For dynamic braking, a built-in brake chopper diverts regenerated energy to an external resistor so the DC bus voltage stays within safe limits during deceleration. Grid compatibility is supported by an integrated line filter that attenuates conducted emissions without requiring separate line reactors. The control electronics remain active during line interruption because the unit accepts 24 V standby power from an auxiliary supply, allowing control functions to remain available when the main input is temporarily unavailable.