Product Description:

The 175U3049 brake resistor is manufactured by Danfoss as part of the VLT Brake Resistors series. It is installed on the DC link of a variable-frequency drive to convert surplus kinetic energy into heat during rapid deceleration or with overhauling loads, thereby protecting the drive and motor from overvoltage events in industrial automation. This passive device uses a wire-wound element secured in a ventilated sheet-metal housing.

The element is rated for continuous dissipation of 2200 W, allowing it to handle routine braking cycles without an excessive temperature rise. For intermittent events, it can absorb short bursts of 27.3 kW at a 10% duty cycle or 6.8 kW at a 40% duty cycle, providing two clear thermal sizing points. Its electrical resistance is 19 Ω with a tolerance of ±10%, which maintains predictable current flow through the DC link. The resistor can be connected to drives that apply up to 800 V across its terminals. An M5 PE stud provides the protective earth connection required for safe fault clearing. A cable strip length of 12 mm allows the conductor strands to seat fully inside the compression terminals without arcing.

The housing meets the IP21 ingress protection rating, so it excludes vertically dripping water and solid objects larger than 12 mm when mounted upright. Insulation integrity is supported by a dielectric withstand rating of 2500 V AC for one minute between the resistor element and the enclosure. An internal bimetal switch with a normally closed contact opens at 180 °C to signal an overtemperature condition. Its alarm contacts can carry up to 2 A at 250 V AC, and the control connection supports insulation for 500 V systems. Control leads require an 8 mm strip length for secure termination. The assembly weighs 11 kg, which must be considered when selecting panel supports and accounting for vibration in the final installation.