Braking resistor for Altivar 71 drives
The VW3A7810 is a braking resistor from the Schneider Altivar range, designed to dissipate regenerative energy from an Altivar 71 drive during deceleration. It is rated at 44 kW average power at 50 °C ambient, with an ohmic value of 1.4 Ohm — this resistance determines the braking torque curve and the peak current the drive's DC bus sees during dynamic braking. The resistor is protected by a thermal overload relay integrated into the assembly, which opens the control circuit if the resistor exceeds safe temperature — preventing fire or enclosure damage in a sustained braking event. The IP23 enclosure allows installation in a ventilated electrical room where dripping water or small debris may be present, but not in washdown or outdoor locations. Electrical connection is via M10 bar terminals, sized for the high current this resistor can handle — expect lug-type cables with ring terminals. The physical footprint is substantial: 1040 mm wide × 620 mm deep × 1150 mm high, so panel layout must account for the floor space and clearance for airflow around the resistor banks.
The VW3A7810 is classified as obsolete by Schneider Electric. No production-status claim is made beyond the official obsolete designation.