Product Description:

The RZK01.1-160-BW is a cabinet-mounted heat exchanger and brake resistor produced by Bosch Rexroth Indramat within the RZK Heat Exchangers series. In multi-axis drive systems, it absorbs regenerative energy that appears on the DC bus during fast deceleration, converts that energy to heat, and expels the heat into the surrounding air stream. By doing so, the unit helps prevent DC-bus overvoltage while protecting connected inverters during repeated braking events. It is intended for installation inside control cabinets where braking energy must be managed without adding a separate external resistor assembly. The combined design also supports stable thermal conditions in enclosed drive systems that run through frequent stop-and-go motion profiles.

The exchanger supplies a continuous cooling capacity of 4 kW, enough to match the nominal braking losses of medium-power drives. Cabinet layout is supported by a compact housing that measures 350 mm deep and 340 mm high. It must be installed with 100 mm of bottom clearance plus 200 mm of free space above the top air outlet so that convection is not restricted. The resistor element presents 2.2 Ω of electrical resistance and connects directly to the DC link through cables up to 5 m long. All live parts remain behind an IP20 touch-safe cover, allowing placement inside standard control enclosures without extra guarding. This arrangement keeps the braking path short and helps simplify internal cabinet wiring around the drive system.

The braking circuit can accept short bursts up to 270 kW for 0.1 s, enabling rapid stops or emergency shutdowns without overvoltage trips, and its nominal dissipation limit is 2 kW for steady cycles. Thermal behavior has a time constant of 13.6 s, so recent braking load can be taken into account before another high-energy stop is demanded. Surface temperature is permitted to reach 80 °C, so heat-sensitive wiring and nearby plastic parts should be kept at an appropriate distance. The steel enclosure weighs 16 kg, which adds rigidity to the assembly while still allowing straightforward cabinet installation. This balance of short-term overload handling and controlled heat release is useful in applications with repeated deceleration and frequent regeneration on the shared DC bus.