Product Description:

The RZW02.1-001-025 braking module is manufactured by Bosch Rexroth Indramat for the RZW Braking Resistors series. It is installed across the DC bus of servo inverters to dissipate regenerated energy during motor deceleration. By converting excess electrical power into heat, the module keeps the intermediate-circuit voltage within safe limits and prevents drive overvoltage faults in automated machinery. This function is particularly important when a motor slows quickly or when a driven load returns energy to the inverter.

The element’s nominal resistance is 120 Ω, so the current flowing during each braking pulse is limited to a predictable value. The minimum connectable resistance is 30 Ω, which is the lowest permitted value when units are wired in parallel. Its continuous thermal capacity is rated at 1.5 kW, but the resistor has a maximum on-time of 30 s and must remain idle for at least 90 s. These intervals produce a 120-second load cycle with an operating factor of 25% SD. The peak-to-continuous ratio of 3.2 permits short energy bursts at 3.2 times the steady-state limit without overheating the element. The module measures 92 mm deep, 120 mm high, and 386 mm wide, allowing installation beside drive controllers in an electrical cabinet. It uses the standardized A1 resistor type with Design 1 and Line 2.

The IP20 protection class shields live parts against accidental contact while leaving the enclosure open enough for natural convection. During operation, the aluminum housing may reach a surface temperature of 80 °C, so adequate clearance is necessary around the installed module. Its thermal time constant is 300 s, representing the time required for the housing to reach 63% of a step change in temperature. The assembly weighs 1.8 kg, allowing it to be mounted directly on a suitable perforated panel without heavy structural support. Heat must be allowed to escape from the mounting area so that nearby drive components are not exposed to excessive temperatures.