Product Description:

The HLL05.1W-04M0-S0303-N-11-01U2-NNNN is identified by Bosch Rexroth Indramat as a DC bus choke belonging to the HLL Bus Chokes series. Installed between the rectifier and the DC link capacitors, the choke introduces inductance that filters high-frequency components and moderates peak charging currents. By stabilizing the bus voltage, it protects downstream servo or inverter drives from voltage overshoot and extends capacitor life in industrial automation assemblies.

The open-frame construction has an IP00 degree of protection, so the unit must be mounted inside a cabinet that provides its own touch-safe barrier and cooling airflow. Its winding insulation and conductor spacing support a nominal bus level of 1100 V DC, matching the intermediate circuits of high-power IndraDrive converters. Reliable service is maintained while the surrounding air remains below 50 °C; above this point, the inductance and insulation margins start to decline. A built-in temperature monitor signals thermal overload. The auxiliary contact is rated for 250 V AC instrumentation circuits or logic supplies up to 24 V DC, and it responds when the winding reaches 160 °C. Integrating this signal into the drive controller allows a controlled shutdown before insulation limits are exceeded.

The switching element of the temperature monitor is wired as a normally closed (N/C) contact, remaining closed during normal operation and opening when the internal core reaches the trip temperature. This arrangement supports fail-safe operation because a broken monitoring connection can be detected in the same manner as an overtemperature event. With an unpacked mass of 44 kg, the unit requires appropriate panel reinforcement and lifting aids during installation. Monitoring the actual core temperature rather than ambient conditions allows ventilation or liquid cooling to be sized for the converter’s duty cycle and switching frequency.