RZW02.1-090-040

Product Description:

Bosch Rexroth Indramat manufactured the RZW02.1-090-040. With a 90 kW output, the Bosch Rexroth Indramat RZW02.1-090-040 brake resistor is designed for demanding industrial braking situations. In high inertia motion systems where the kinetic energy produced during motor braking has to be converted into thermal energy as quickly and safely as possible, this number is crucial. The resistor’s ability to maintain high power levels allows for more frequent stops and shorter braking times, which means better machine cycle time and productivity. The resistor is Type F and has a fixed resistance component with a steel screen design. A fixed resistor ensures that the component’s resistance is constant as it operates. Both mechanically and thermally, the steel screen protects the internal resistive parts. It also provides a means of transmitting and radiating heat away from the resistor core. Steel is a good choice for industrial applications where heat cycling and physical impacts are common because of its toughness and low thermal conductivity.

In addition to improving life under mechanical and electrical stress, this design allows for steady heat transfer to the surrounding air, which is important when working with high peak energy loads that can stress the resistor during fast deceleration cycles. A 40% operating factor means the device’s duty cycle, which limits the time it can actively waste energy to 40% of the overall cycle time. The ratio controls how active braking and cooling times are balanced. A 40% duty cycle is an important limit that ensures the resistor’s body temperature stays below acceptable limits during prolonged or frequent braking and reflects thermal design assumptions. Thermal saturation can occur if this threshold is exceeded and can lead to mechanical fatigue, resistive drift or insulation failure. Engineers must, therefore, plan the motion profile to provide sufficient recovery times, especially in high-frequency braking applications.

A thermal time constant of 100 seconds, which describes how fast the resistor’s temperature changes in response to changes in power dissipation, defines thermal management. This size of the time constant means a slow thermal response, which means the resistor can absorb short-duration high-power pulses without temperature spikes. The resistor takes a long time to cool down after heating up, which is why proper duty cycling and ventilation are crucial. With an IP20 rating, the component is protected against moisture but not against fingers or solid objects larger than 12.5 mm. A 3-phase, 400 V, 50 Hz axial fan with a 3.5 kVA rating is required for forced ventilation. Under continuous or semi-continuous loads, this fan ensures the convective heat transfer rate is high enough to match the heat input. Without forced airflow, the resistor can exceed its temperature limits and compromise system stability and safety.