Product Description:

The RND01.1-4-185 is a three-phase mains choke produced by Bosch Rexroth Indramat within the RND Three Phase Mains Chokes series. Installed on the supply side of converters or inverters, it limits current peaks and attenuates harmonic distortion in power networks. By adding series inductance, the choke protects downstream drives and reduces electromagnetic interference. It is mounted close to the converter input and operates without its own control electronics.

During operation, the choke carries a 300 A continuous line current, so conductors and upstream protection devices must be selected for that load. Internal copper and core losses reach 2.5 kW, so a cooling fan delivering 1000 m³/h of air is required to keep the winding temperature within limits. The device is supplied with M10 / 95 mm² screw clamp terminals, enabling direct connection of large three-phase cables. The unit has an IP00 enclosure rating, which means the coil assembly is not shrouded and must be mounted inside a closed electrical cabinet. Two 11 × 18 mm longitudinal slots and a mounting width of 430 mm simplify mounting to the back panel, while a built-in thermal switch rated at 30 V and 1 A is wired with 1.5 mm² conductors to signal an overtemperature condition to the drive controller.

With a nominal reactive impedance matched to a drive system up to 185 kW, the unit fits medium-power pump, press, and conveyor installations. It belongs to category 3K3, so it is intended for control rooms where temperature and humidity are controlled and conductive dust is absent. The line lugs must be tightened to 35 Nm to maintain stable contact under vibration, and the laminated core brings the total mass to 125 kg, requiring a rigid panel or floor support. The overall width is 510 mm, the height is 425 mm, and the depth is 225 mm, leaving room for airflow guides and access to the thermal switch circuit.