Product Description:

The RZW03.1-075-006 braking resistor is manufactured by Bosch Rexroth Indramat for the RZW Braking Resistors series. Installed on the DC bus of a drive converter, the unit dissipates surplus kinetic energy as heat and protects the inverter from voltage surges during controlled braking. It follows Design 1 and measures 595 mm wide, 520 mm high, and 490 mm deep, making its dimensions suitable for installation on panel rails or inside a free-standing enclosure.

The resistor element has a nominal resistance of 4.9 Ω, and the connected drive must not use a load below the required minimum resistance of 3.75 Ω. Its continuous absorption capacity of 75 kW allows it to handle the high pulse energy produced by rapidly decelerating large-inertia axes. Thermal energy disperses through finned steel plates, and the assembly has a thermal time constant of 100 s. This time constant represents the period required for the temperature to reach 63% of its final change after a step in applied power. The permissible duty cycle is 6% SD, so power may flow through the resistor only during short intervals. Connections to the terminals require conductors with a cross-sectional area of 25 mm² to support the current associated with the resistor’s power capacity.

Each operating cycle permits a maximum energized duration of 7.2 s, followed by a mandatory recovery period of 112.8 s. Following these timing limits prevents excessive internal temperatures and allows the resistor to release accumulated heat before the next braking pulse. The housing has an ingress protection rating of IP23, which blocks solid objects larger than 12 mm and protects against water spray at angles of up to 60 degrees from vertical. The resistor has a total weight of 36 kg, providing thermal mass that helps absorb the heat generated during short braking cycles. Passive cooling allows the module to operate without external fans or liquid-cooling equipment when the required installation clearances and operating limits are observed.