Product Description:

The RZK01.1-132-BW is a heat-exchanger module produced by Bosch Rexroth Indramat within the RZK Heat Exchangers series. It mounts outside an electrical cabinet and removes heat generated by braking resistors in drive systems. In automated lines, it absorbs short energy surges during deceleration and releases the resulting heat through airflow. This helps protect cabinet-mounted electronics and keeps internal temperatures from rising during repeated braking events.

The unit provides 4 kW of cooling power, so it can transfer a continuous thermal load from the resistor to the surrounding air. Under standard duty, the resistor is rated for 2 kW nominal power, which supports sustained operation without excessive heating. The internal resistance is 2.2 Ω, which sets the current drawn when the DC bus voltage is limited. During an emergency stop, the assembly withstands 270 kW peak power for 0.1 s to absorb a brief braking surge. The housing may reach 80 °C during operation, and the module is connected by two 16 mm² brake conductors and one 16 mm² ground conductor. A single heat-exchanger core routes air through the fin stack to carry heat away from the resistor body.

The thermal response follows a 13.6 s thermal time constant, so casing temperature changes with a short delay after the load changes. At least 200 mm of clearance is required above the unit so natural convection is not restricted, and the external mounting position keeps hot exhaust away from sensitive drive components. The enclosure is rated IP20, which helps prevent accidental contact with live parts but is not intended to seal out dust or water. With a mass of 16 kg, the module remains compact enough for external cabinet mounting. Its layout supports resistor cooling without adding heat directly to the enclosure interior.