Product Description:

The HLL05.1F-04M0-S0243-N-D7-01U2-NNNN bus choke is produced by Bosch Rexroth Indramat within the HLL Bus Chokes series. This passive line component is installed in the DC link of an Indramat drive system to smooth current ripple and protect connected inverters from peak voltages. By increasing the effective inductance of the link, the choke limits di/dt, reduces switching stress on connected power sections, and mitigates commutation noise in automated motion or machining installations. In plant automation cabinets, it works between the rectifier and the drive modules, where stable bus behavior helps support repeatable axis response during acceleration and regeneration. That role is especially useful in systems where several axes share a common DC bus and return energy during deceleration.

The choke core is enclosed in a liquid-cooling jacket, so heat generated by copper and iron losses is transferred to a plant coolant circuit instead of the control enclosure air. Under continuous load, the winding carries a nominal current of 243 A, and the unit provides a nominal inductance of 4 mH on the link to moderate current ramps during regenerative events and rapid load changes. The insulation spacing supports a DC bus potential up to 750 VDC, while the built-in normally closed temperature switch can be supervised through circuits rated for 250 VAC. Because the assembly is classified as IP00, it must be installed behind protective covers to prevent accidental contact with energized parts. Liquid cooling also helps prevent the choke from adding excess heat to tightly packed control cabinets.

The temperature sensor inside the winding is a normally closed contact that opens at 160 °C, issuing an alarm through either the 24 VDC control circuit or a 1 A monitoring line so the drive can be disabled before insulation limits are exceeded. A current-compensated winding layout reduces common-mode interference and keeps leakage capacitance to 1.2 µF, which helps limit ground currents when high-frequency content is present on the bus. The assembly weighs 25 kg, and it should be bolted to a coolant plate so the thermal path and mounting surface remain secure during operation. Full contact at the mounting surface also helps maintain consistent heat transfer during long duty cycles and repeated regenerative loading.