Product Description:

The RD42.1-4R-026-L is a three-phase converter drive controller manufactured by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. Positioned between the mains supply and the motor branch, the unit rectifies and stabilizes AC power so downstream inverters receive a controlled DC link. In automated packaging lines, material-handling cells, and process skids, it supervises faults, balances electrical load, and transmits status information to a higher-level PLC. This arrangement allows the controller to manage power flow between the incoming supply and connected drive sections during changing operating conditions.

Its power section uses a three-phase AC converter topology and accepts line voltage from 380 to 480 V. The input stage permits a deviation of ±10%, which helps prevent nuisance trips during normal grid fluctuations. An integrated mains filter attenuates conducted emissions, reducing the need for additional upstream RFI components. Thermal control relies on forced air cooling, so airflow through the heat-sink passages must be maintained for rated current delivery. The unit can feed multiple inverters from a common DC link while helping control harmonic distortion and temperature rise during continuous operation.

The unit is built as design 1 and comes without a brake chopper, so excess DC-bus voltage during deceleration is handled through energy recovery back to the supply rather than by resistive dumping. When rapid dynamic braking is required, an external chopper module must be installed. Parameter sets and diagnostics remain consistent across the platform, which keeps operation and fault tracing straightforward. Regenerative operation also reduces the amount of heat that would otherwise be released inside the control cabinet during repeated deceleration cycles.