FAQ - What’s the Difference Between a Braking Resistor and a Regenerative Braking Unit?

Q: What’s the Difference Between a Braking Resistor and a Regenerative Braking Unit?

A: 

A braking resistor dissipates excess motor energy as heat to prevent overvoltage, while a regenerative braking unit captures that energy and returns it to the power supply or a battery, improving efficiency and reducing waste. 

Braking Resistor (DB Resistor)

A braking resistor is an electrical switch that manages the DC bus voltage by switching the braking energy to a resistor, where the braking energy is converted to heat, to safely dissipate excess energy as heat when the motor slows down.

• Prevents overvoltage on the inverter's DC bus.

• Ideal for occasional or moderate braking needs.

• The MX2-V2 includes a built-in braking transistor, allowing direct connection of an external resistor.

Regenerative Braking Unit (RBU)

A Regenerative Braking Unit returns the regenerative energy back into the power grid rather than dissipating it as heat. Converts regenerative energy into usable electrical power for return to the supply line. enhances braking performance by working with a braking resistor to more effectively manage high regenerative loads.

• Helps control energy flow during frequent or heavy braking.

• Ensures stable operation and reduces the chance of inverter overvoltage trips.

• Suitable for applications like elevators, conveyors, cranes, or high-inertia loads.

Note: Always verify compatibility and settings using the datasheets and consult with our technical support when in doubt.

Date/Revision History

First review 9/15/2025 V1.0

Author: 

Aimee Rivera, Technical Support Engineer

References

MX2-V2 Datasheet