Product Description:

The RD51.3-8C-090-L-NN-FW is a drive controller produced by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. Within an automation cell, it serves as the inverter stage, receiving DC power and modulating it for motor and process loads that operate from the same bus. This arrangement supports coordinated speed and torque behavior across multiple axes where a shared energy source is used. Because the unit works from a central DC supply, it fits systems that distribute power across several inverter positions instead of feeding each drive directly from the AC line.

Control is delivered through U/f curve control, so the output frequency follows a preset voltage-to-frequency profile and induction machines can run without closed-loop feedback. This method suits applications that need reliable speed control without encoder-based regulation. Thermal management uses forced air cooling, with a fan moving cabinet air across the heat sink to keep semiconductor temperatures within limits. The unit is supplied from an inverter DC link rather than line-connected AC, which allows several drives to share a common supply rail. Under these conditions, it delivers 90 kW for large process loads. Its bus hardware is rated for 700 V, so the DC link must remain within that limit during operation and braking.

The unit belongs to Generation 3, which marks the revision level used for this model in the product line. It is classified as a drive controller and is configured for operation as RD51 SFT, which enables parameter sets intended for soft-torque applications. This version is used where smooth speed regulation and controlled torque response are required on a shared DC-bus system. Optional communication functions are not equipped in this configuration, so the unit remains focused on its core inverter role.