Product Description:

The 20.DR.B18-3341 input choke is manufactured by KEB as part of the DR Motor Input Chokes series. This three-phase line reactor is installed between the utility supply and an AC drive to suppress harmonics, reduce commutation noise, and limit inrush current in automated machinery. By inserting additional inductance into the supply path, it helps protect drive rectifiers, stabilize the drive input, and support electromagnetic compatibility in production lines.

The choke has an inductance of 0.33 mH, which filters switching ripple while keeping the voltage drop within acceptable limits. The winding supports a continuous load of 90 A, enabling connection to drives that deliver up to 37 kW of mechanical power to the motor. Designed for networks in the 400 V class, the choke maintains its operating characteristics across a supply frequency range of 45–65 Hz. This range allows the unit to operate with equipment connected to either 50 Hz or 60 Hz utility power. Its electrical characteristics make it suitable for installation at the front end of an inverter cabinet, where the reactor can reduce disturbances entering or leaving the drive system.

The choke’s series impedance produces a short-circuit voltage of 4%; this value indicates the line voltage drop at nominal current and the resulting fault-current limitation. Total thermal dissipation at full load is 151 W, a heat level that normally requires forced ventilation in compact control panels. Cable lugs for conductors up to 35 mm² fit the terminals and provide enough conductor area to keep connection temperatures low. The laminated core and windings are housed in a frame that is 267 mm wide and 186 mm deep. Installation uses 7 × 12 mm slotted holes that accept standard M6 screws. The balanced winding arrangement distributes magnetic flux evenly and helps reduce audible hum during operation.