Product Description:

The RZW01.1-018-NNN braking resistor is produced by Bosch Rexroth Indramat within the RZW Braking Resistors series. As a discrete power-dissipation module, it works with Rexroth inverters to absorb excess DC-bus energy generated during rapid motor deceleration, helping maintain a safe bus voltage in automated machinery. By converting surplus electrical energy into heat, the device protects drive semiconductors and prevents nuisance overvoltage faults in conveyor lines, machine tools, and packaging equipment.

This model has a continuous energy absorption rating of 18.5 kW. Its resistive path measures 17.5 Ω, which determines the current drawn from the drive when the chopper circuit switches on. Its thermal response has a time constant of 185 s, indicating how quickly the housing approaches a steady-state temperature after a power surge. To remove heat, the unit relies on converter exhaust air passing across finned aluminum channels. The housing temperature must remain below 100 °C to preserve the ceramic insulation blocks that isolate the internal metal-alloy element. These thermal limits govern the permissible operating duty and help prevent overheating during repeated braking cycles.

The mounting grid measures 22.5 mm, and the resistor must be installed perpendicular to the airflow. A minimum top clearance of 100 mm is required to provide unobstructed ventilation around the unit. The assembly belongs to size class B and weighs 2.3 kg, allowing it to be attached to standard control-cabinet backplates without excessive support hardware. An aluminum shell encloses the metal-alloy strip, while ceramic spacers provide electrical insulation between energized components and the housing. The unit uses design code 1 and line code 1 for compatibility with first-generation RZW chopper modules. Air from the converter passes through the cooling fins to carry heat away from the resistor during operation.