Product Description:

The RZW02.1-004-015 braking resistor is manufactured by Bosch Rexroth Indramat and belongs to the RZW Braking Resistors series. This discrete, convection-cooled module absorbs regenerative energy from Rexroth drive controllers, keeping the DC-link voltage within safe limits during deceleration. The module uses Design 1 and Line 2 and has a compact profile that fits inside control cabinets.

The resistor has a power rating of 4 kW, allowing it to dissipate electrical energy as heat when operated within its permitted duty cycle. Its element provides a resistance of 47 Ω, which draws the required braking current from a 600 V class bus without exceeding the power rating. The operating factor is 15% SD, so the resistor should be energized only for short intervals to keep average power within safe limits. The IP20 enclosure guards against contact by fingers and similarly sized objects while maintaining the airflow needed for cooling. The resistive element has a thermal time constant of 300 s, so its temperature rises gradually and permits brief overloads before reaching steady-state conditions. Installation requires a protective grounding conductor with a minimum cross-sectional area of 10 mm², while control leads may have a cross-sectional area of up to 2.5 mm².

The resistor has a maximum on-time of 18 s followed by an off-time of 102 s; this timing prevents excessive heat buildup during repetitive braking events. When several resistors are connected in parallel, the resistance of each branch must not fall below 30 Ω to avoid excessive current. The assembly weighs 2.8 kg and measures 586 mm high, 92 mm wide, and 120 mm deep, allowing vertical installation on a cabinet backplate. Its A21 resistor element is housed in a perforated sheet-steel frame that supports free convection, while the internal leads have a cross-sectional area of 2.5 mm² to limit temperature rise around the connections.