DBR 8kw to 60kw Series Dynamic Braking Resistors
Customer-engineered dynamic braking resistors designed to absorb regenerative energy from variable-speed drive systems during motor deceleration
Power rating 8 kW to 60 kW
Resistance range 1 Ω to 150 Ω
Tolerance options ±5% and ±10%
TCR 800 ppm/°C maximum
Built to customer specification to match drive rating, duty cycle, and enclosure requirements
Designed to meet or exceed all relevant industry standards
ISO 9001 and IATF 16949 certified manufacturer
What are the DBR 8kw to 60kw Series Dynamic Braking Resistors?
The DBR is a high-power dynamic braking resistor designed by RARA Electronics to protect variable-frequency drive (VFD) systems and their associated motors from the damaging effects of regenerative energy during rapid deceleration. When a motor is commanded to decelerate or is driven by an overhauling load, it transitions from consuming electrical power to generating it, producing a back electromotive force that feeds energy back into the DC bus of the drive. Approximately eighty percent of this regenerated energy must be absorbed externally to prevent an overvoltage condition that would otherwise trip or damage the drive. The DBR is connected across the DC bus through a brake chopper transistor within the drive, which switches the resistor into circuit whenever the bus voltage rises above the threshold, dissipating the excess energy as heat.
Each DBR unit is customer-designed to the power rating, resistance value, duty cycle, and enclosure configuration required by the specific drive installation. Power ratings span 8 kW to 60 kW, covering the braking duty requirements of the drive systems most commonly encountered in industrial plant and process applications. The resistance range of 1 Ω to 150 Ω encompasses the values needed to set braking torque at 100% or 150% of motor rated torque, with lower resistance values delivering higher braking current and faster motor stops. Tolerance options of ±5% and ±10% are available to match the sensitivity of the brake chopper threshold and drive protection settings.
The resistive elements are constructed for repetitive high-energy transient duty, with sufficient thermal mass and surface area to handle the peak energy of each braking cycle without exceeding safe element temperatures. Duty cycle is a critical parameter in DBR selection: for normal deceleration braking, the resistor wattage is determined by the product of the drive power and the duty cycle divided by two, with a maximum single on-time of sixty seconds. For continuous overhauling load conditions — where the load is permanently driving the motor rather than being driven by it — the full continuous power rating of the resistor must equal the regenerated power of the drive. RARA engineers each unit to the specific regeneration type and duty cycle provided by the customer, ensuring that the resistor is correctly rated for the thermal demands of the application rather than being specified conservatively from a fixed catalogue.
DBR 8kw to 60kw Series Dynamic Braking Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
Model: DBR
Resistor type: High Power
Description: Dynamic Braking
Power Rating: 8KW~60KW
Resistance (Ω): 1~150
Tolerance (%): ±5, ±10
TCR (ppm/C): 800 (max.)
Applications of the DBR 8kw to 60kw Series Dynamic Braking Resistors
Where RARA metal clad resistors are deployed in the field.
-Variable-frequency drive systems on industrial machinery — absorbing regenerative energy during controlled deceleration of large motors driving conveyors, compressors, pumps, and fans in manufacturing and process plant environments
-Crane and hoist drives — dissipating the gravitational potential energy regenerated by crane bridge, trolley, and hoist motors during lowering and controlled stops, where rapid and repeatable braking is essential for safe load handling
-Elevator and lift systems — absorbing braking energy during car deceleration and overhauling descent, reducing mechanical brake wear and enabling smooth, controlled stopping across a high duty cycle
-Industrial conveyor and material handling systems — providing braking torque during belt deceleration on inclined conveyors and transfer systems where loaded belts would otherwise drive the motor as a generator
-Marine vessel and offshore platform drives — protecting thruster and auxiliary drive systems during rapid deceleration manoeuvres in marine environments where robust enclosure construction and vibration resistance are required
-Renewable energy wind turbine systems — dissipating regenerative energy from pitch and yaw drive motors during emergency stops and grid fault events, protecting the VFD from overvoltage during rapid rotor deceleration
-Test bench and dynamometer systems — absorbing the full regenerated power of motors under load in continuous overhauling conditions during endurance and performance testing of drive systems and rotating machinery
-Rolling mill and metal processing drives — managing the high regenerative energy produced by coiler, uncoiler, and roller table drives during process stops and tension control reversals in steel and aluminium production
Related Products of the DBR 8kw to 60kw Series Dynamic Braking Resistors
Model: RA
Resistor type: Metal clad resistor
Description: Assembly
Power Rating: 80W~750W
Resistance (Ω): 0.1~2.2k
Tolerance (%): ±0.5, ±1, ±2, ±5, ±10
TCR (ppm/C): 260 Max.
Model: HRA
Resistor type: Metal clad resistor
Description: Assembly
Power Rating: 520W-2500W
Resistance (Ω): 0.1~1.6k
Tolerance (%): ±0.5, ±1, ±2, ±5, ±10
TCR (ppm/C): 260 Max.
Model: MCS
Resistor type: High Power Braking
Description: Industrial
Power Rating:2kW-3.4kW
Resistance (Ω): 0.1~9k
Tolerance (%): ±1, ±5, ±10
TCR (ppm/C):
Model: IRVA
Resistor type: Metal clad resistor
Description: Chassis mounted assembly
Power Rating: 300W-450W
Resistance (Ω): 30~15k
Tolerance (%): ±1, ±2, ±5, ±10
TCR (ppm/C): 260 Max.
Why Choose RARA Metal Clad Resistors
What sets RARA apart for engineers and procurement managers in industrial and automotive markets.
01
Automotive Qualified
AEC-Q200 tested models and IATF 16949 certification for EV and automotive powertrain applications. Trusted by GM Korea, Tesla, and Proterra.
02
STEP Files Included
3D STEP files available for core models, supporting ECAD/MCAD integration and thermal management simulation in your design workflow.
03
Wide Power Range
A single product family spanning 10W to 8.5kW means you can source across a project from one qualified, certified supplier.
04
Global Track Record
Deployed by Siemens, Rockwell, Toshiba, Schneider Electric, LG, and Hanwha — a customer list built on decades of consistent performance.
