RZW02.1-160-006

Product Description:

Bosch Rexroth Indramat manufactured the RZW02.1-160-006. The RZW02.1-160-006 brake resistor converts electrical energy into heat during electric drive deceleration, and its design can withstand a continuous power dissipation of 160 kW. In industrial automation, especially in regenerative braking systems, this avoids DC bus overvoltage situations, which can damage or destroy the drive. Power dissipation is time-related from a physics perspective, and a continuous rating of 160 kW means the resistor can handle big thermal loads without degrading. The transient performance of this resistor is determined by its 144 kW peak power rating at 40% switching duty cycle. The percentage of time the resistor is active is measured by the switching duty cycle. 40% means 40% of the time the resistor is in operation, and 60% is used for cooling. The highest thermal energy it can absorb during those active periods is reflected in the peak rating under this limitation.

The electrical properties of the resistor also show how it behaves under different load scenarios. For a 40% and 60% duty cycle, it has a fixed resistance of 4.8 Ω and a minimum connectable resistance of 2.2 Ω. Destructive thermal runaway is avoided by keeping the current draw within safe limits for the resistor and driving by the lowest permissible resistance. Predictable braking torque and energy dissipation are achieved by the same resistance values for different duty cycles, which means the current and voltage working ranges are set. To ensure thermal balance and prevent oversizing or underutilization, which both reduce system efficiency, engineers sizing brake resistors in servo-driven systems must match these characteristics with drive voltage levels and braking profiles.

The technical profile of the RZW02.1-160-006 is completed by the mechanical design and thermal behavior. The resistor has a slow temperature response with a thermal time constant of 150 seconds, which could be due to restricted natural convection or too much thermal mass. To counter this, the unit has an axial ventilator, which provides forced convection to keep thermal balance when operating at high loads. By increasing the heat transfer coefficients, this active cooling allows the resistor to handle its rated power dissipation without overheating. Although the IP20 classification limits its application to dry and clean areas where liquid and particle infiltration is unlikely, the galvanized steel housing ensures structural integrity and corrosion resistance. The conductor cross-sections of 95 mm² for 40% duty and 2 x 50 mm² for 60% duty are most likely the internal wire dimensions and show heat conduction paths and current handling capacity.