Product Description:

The 27.DR.B28-1041 is a three-phase motor input choke manufactured by KEB as a member of the DR Motor Input Chokes series. Positioned at the input of a variable-frequency drive, the component adds inductance to the mains line to reduce differential current peaks, limit commutation noise, and extend the service life of downstream power electronics used in industrial automation. KEB supplies the assembly as a passive line reactor that works with its inverter portfolio, giving machine builders a way to comply with power-quality limits and protect motor insulation from steep voltage edges.

The choke has an inductance of 0.10 mH, which provides reactance for filtering higher-frequency harmonics while keeping the fundamental voltage drop low. It is rated for a nominal current of 300 A, so it can be installed ahead of sizable inverters without saturation. Its insulation system has a voltage class of 400 V, matching typical low-voltage distribution networks. A short-circuit voltage of 4% indicates the relative voltage drop across the device at nominal load, which must be considered when sizing upstream fuses and circuit breakers. Internal copper and core losses total 308 W under full load. Integrated temperature detection switches provide thermal monitoring to prevent the resulting heat from exceeding safe operating limits.

Mounting slots measuring 10 × 16 mm align with common cabinet subplates and provide secure attachment points. The laminated core has branches for three phases, ensuring balanced impedance for symmetrical line currents. Power conductors connect to rigid busbars drilled and tapped for M12 terminals, promoting low contact resistance at high current levels. The choke weighs 48.2 kg, so stable support and suitable lifting equipment are recommended during installation. Adequate clearance around the mounted assembly also helps prevent nearby wiring or components from interfering with its terminals and temperature monitoring connections.