Issue:
Why is the dynamic braking resistor repeatedly failing in our lift application?

Product Line:
Dynamic braking resistors, Altivar 71

Environment:
Lifting applications

Cause:
DBR failure

Resolution:
Generally, the dynamic braking resistors burning or failure happens due to higher braking energy dissipation than it's power rating.
If you select the normal braking resistor part reference provided in the catalog, the power rating of the resistor is insufficient to dissipate the braking energy generated by the motor in during downward movement. Hence it will burn the resistor due to overheating.

The lift is a vertical and cyclic movement application, and the braking power dissipation is similar to hoisting application. Hence it is necessary to select the hoisting resistor part references provided in the ATV71 catalog to avoid DBR failure due to overbraking.

Released for: Schneider Electric Egypt and North East Africa