Product Description:

The RD51.1-4B-090-L-V1-FW is a drive controller manufactured by Bosch Rexroth Indramat for the RD 500 Drive Controllers series. By converting fixed-frequency mains power into a variable output, the unit governs induction-motor speed and torque in automated material-handling, pumping, and processing lines. It is intended for cabinet-mounted industrial applications where controlled acceleration, steady running, and coordinated deceleration are needed to support reliable machine operation over repeated duty cycles. This operating method also helps reduce electrical stress on connected motors compared with direct-on-line starting.

This controller operates on a line voltage window of 380 to 480 V and accepts supply fluctuations within a ±10 % tolerance, allowing connection to common factory power networks. It delivers up to 90 kW of motor power and uses U/f curve control to match output voltage to frequency so the motor remains properly magnetized across its operating range. The electronic assembly uses forced air cooling, with a fan moving cabinet air across heat-generating components so the unit can sustain rated output during continuous industrial duty. The controller is built in design generation 1, following the first mechanical and electrical layout released for the RD 500 platform.

The power stage uses a three-phase AC converter front end that rectifies and inverts the incoming mains supply for the motor output section. Dynamic braking is supported by a built-in brake chopper, which directs excess DC-bus energy to external resistors during rapid deceleration or overhauling loads and helps prevent overvoltage shutdowns. An integrated mains filter reduces conducted emissions, and an external source can feed the dedicated 24 V stand-by power input so diagnostics and interface electronics can remain active when the main supply is removed. Keeping the control supply separate allows status information to remain available during controlled shutdowns and other power-off conditions.