Product Description:

The RD51.2-4B-005-L-A1-FW is a drive controller manufactured by Bosch Rexroth Indramat as part of the RD 500 Drive Controllers series. The module accepts three-phase AC power and modulates motor speed through U/f curve control, allowing induction machines to follow commanded process profiles in automated conveyor, pump, or fan stations. A built-in brake chopper dissipates regenerated energy, while an integrated mains filter limits line-borne interference. Forced-air cooling keeps semiconductor temperatures stable, so the device is intended for installation inside protected control cabinets.

During continuous operation, the controller supplies a rated apparent power of 4.6 kVA at a rated current of 7 A and maintains output within a ±10% mains tolerance. The brake chopper can absorb 2.8 kW continuously and handle bursts up to 18 kW for one second, provided a 35 Ω external resistor is connected. Thermal management relies on air, and the blower must move 0.03 m³/s of cooling air through the heat sink channels. An enclosure rating of IP20 means the unit requires panel shielding against dust and accidental contact. For overload situations, it can deliver a peak apparent power of 6.0 kVA for sixty seconds before returning to nominal limits.

Supervisory features include standby power supplied externally and a starting lockout that inhibits unintended motor starts until the control circuit is enabled. This behavior helps prevent unexpected motion after power returns or control voltage is restored. At a 12 kHz switching frequency, the unit allows a peak of 9.1 A during short acceleration periods. Internal dissipation reaches 0.26 kW, so cabinet ventilation must expel that heat in addition to process losses. The unit is design generation 2 and has a fundamental power rating of 5.5 kW, covering medium-power loads fed from a mains window of 380 to 480 V. The self-contained brake circuitry reduces wiring and external component count.