Product Description:

The RZW01.1-075-NNN is a braking resistor manufactured by Bosch Rexroth Indramat within the RZW Braking Resistors series. This component installs on the DC link of a drive controller to dissipate excess regenerative energy as heat during rapid deceleration or operation with overhauling loads, helping prevent overvoltage in automation systems. It converts electrical energy into controlled thermal output through a ceramic-insulated resistive element and is intended for cabinet or panel mounting in industrial machinery.

The resistor is sized for a continuous thermal load of 75 kW, so drives that regenerate below this limit can brake continuously without overheating the unit. For emergency or high-inertia stops, it can absorb a momentary load of 148 kW for 1 s. During this interval, the 4.4 Ω resistance limits peak current while still providing rapid energy discharge. The electrical properties are paired with a thermal time constant of 185 s, which indicates the time required for the housing to reach 63% of its final temperature after a step load. Connections use a single supply line with 10 mm² conductors, and the manufacturer’s ED operating factor permits use with cyclic duty profiles.

The unit belongs to Size Class D and weighs 7.9 kg, so the panel must have rigid mounting points capable of supporting its mass. Its mounting pattern follows a 22.5 mm construction grid, allowing installation alongside compatible hardware when 100 mm of vertical clearance is provided for natural convection. During operation, the aluminum fins may reach a surface temperature of 80 °C, so adjacent cables should be routed away from the hot surfaces. The resistor operates at ambient temperatures from 0 °C to 40 °C and can be stored at temperatures from -25 °C to +70 °C. It also tolerates relative humidity levels up to 90% without condensation, while its Design 1 and Line 1 configuration establishes the terminal orientation.