Product Description:

The RZW01.1-015-NNN is a braking resistor manufactured by Bosch Rexroth Indramat for the RZW Braking Resistors series. Positioned inside a power cabinet, it connects across the DC bus of an inverter or servo drive and converts excess regenerative energy into heat when a motor decelerates or a load overhauls. Using this passive component, an automation system avoids bus overvoltage trips and shortens braking times without adding active electronics. This arrangement is useful in motion systems that return energy to the DC bus during rapid stopping or lowering operations.

The resistor is rated for a continuous dissipation of 15 kW. Its 17.5 Ω impedance limits current while still allowing regenerative energy to be removed quickly from the drive. A Heavy-Duty Metal Alloy element in an aluminum housing provides uniform heating and supports a maximum surface temperature of +100 °C before derating is required. Heat-up follows a 185 s thermal time constant, so short bursts can be absorbed without exceeding material limits. The non-flammable resistive strip is arranged on a 22.5 mm grid that matches DIN rail spacing, and the unit uses ED duty for cyclic operation. The housing also spreads heat over a broad surface so cabinet airflow can carry it away more evenly.

The assembly may be mounted in panels where the ambient air does not exceed 40 °C. At least 100 mm of vertical clearance must be left above the fins to maintain convection flow and prevent heat from collecting around the housing. A protective ground made with a conductor of 10 mm² copper or larger bonds the housing and provides a safe fault-current path. Despite its ability to handle large pulses, the unit adds only 2.3 kg to the enclosure load, which helps limit stress on DIN rail hardware. Proper mounting and grounding are important because the resistor releases braking energy directly as heat during repeated deceleration events.