Product Description:

The DMA 085B 1301-D servo drive module belongs to the DMA Servo Drive Modules series from Bosch Rexroth Indramat. As a three-phase module for synchronous and asynchronous motors, it accepts DC power from a shared rack supply and produces controlled three-phase output for precise motion tasks in automated machinery. This arrangement allows several axes to share one cabinet power source while keeping motor current control inside the individual drive module. A SERCOS setpoint interface carries motion commands, and a standard encoder interface with a 12-bit resolver input returns position feedback for closed-loop control.

During dynamic sequences, the drive can supply a maximum open-loop current of 86 Arms at a 4 kHz switching frequency, while the limit drops to 63 Arms when the carrier is raised to 8 kHz. In closed-loop operation, the continuous current ratings are 47 Arms at 4 kHz and 31 Arms at 8 kHz, which supports sustained duty without excessive thermal rise. The lower switching frequency allows more available current, while the higher carrier setting reduces that margin. The internal DC bus is fed from a common supply unit, and its non-regulated voltage may reach 715 VDC before the inverter stage uses the stored energy.

Thermal dissipation is handled by air drawn across the backplane by two fans, and the design limits semiconductor and copper losses to 380 W under worst-case conditions. The control electronics require only 1.35 A from the 24 V auxiliary rail, which helps keep auxiliary power demand modest inside the rack. When the DC link operates in regulated mode, the bus settles near 670 VDC during steady loading. The module weighs 11.5 kg and occupies 100 mm of rack width, allowing dense placement next to the RMB/DM backplane module that distributes the DC and communication lines. Rear air cooling removes the need for front-panel heat sinks, and the dual-fan layout maintains airflow if one fan stalls.