Branche

Industrial Drive Technology

Reliable braking resistors for frequency converter drives, starting resistors for slip ring motors, and more.

Power resistors for dynamic drive solutions in industry

In modern industrial drive technology, powerful, precisely controllable drive systems are essential. Whether standard or servo motors with frequency converters, slip ring motors or DC motors with current adjusters – wherever motion needs to be regulated, stopped, or dynamically converted, FRIZLEN's braking resistors come into play. Our power-optimized solutions ensure safe dissipation of excess energy generated during regenerative braking in frequency converter operation – reliably, efficiently, and durably.

For these applications, we develop safe, precisely dimensioned braking resistors that are specifically tailored to the requirements of your electric drives. Thanks to our broad product portfolio – from encapsulated flat resistors to compact lamina type and steel grid resistors to custom solutions – we offer you the exact resistance solution that makes your drive technology safer and more efficient.

Typical areas of application for braking resistors include hoists, conveyor systems, machine tools, or elevator systems. Through the close integration of development, manufacturing, and quality assurance, as well as our extensive application experience, we ensure reliable protection against overload and short circuits – even under high peak power or in harsh industrial environments.

With over 100 years of experience in resistor technology, FRIZLEN is your experienced partner for innovative solutions in the field of braking resistors in industrial drive technology.

Braking resistors for frequency converter drives

In certain operating conditions, such as the abrupt deceleration of a machine tool, lowering of loads, or downhill descent, the electric motor switches to generating operation. During this process, kinetic energy is converted into electrical energy. However, this regenerative energy cannot always be fed back into the grid and must therefore be reliably dissipated to prevent overload of the power electronics. This is where the braking resistor – also known as a chopper resistor – comes into play: It converts the excess energy into heat, thus ensuring the necessary protection of the system.

However, the braking resistor not only serves a protective function – it is a crucial factor for the performance and dynamics of an industrial drive system. Only through targeted energy dissipation with a powerful braking resistor can high accelerations and sudden decelerations be safely realized. Particularly in applications with highly variable load conditions or frequent stop-and-go operation, it ensures reliable absorption of peak loads and enables controlled motion sequences.

When choosing the right device, the Product Finder or your contact person at FRIZLEN will assist you.

Brake resistor dimensioning

Use the brake resistor calculator to perform an initial dimensioning of your brake resistor – and send your inquiry directly to FRIZLEN!

Starting resistors for slip ring motors

Slip ring motors are preferred for high drive powers in harsh environments – for example, on crane systems in steelworks, in mining conveyor technology, or during the heavy starting of large machinery. Particularly in the starting phase, it is crucial to limit the high starting current in a targeted manner to avoid mechanical stress and electrical overloads in the system. In order to enable a controlled, "soft start" of the motor, so-called starting and regulating resistors are used. They ensure that the torque is controlled as needed during the start-up process, and the motor speed is gradually increased.

Typically, these resistors are constructed in a stepped manner: this means that several partial resistors are integrated into one device and are sequentially short-circuited during the starting phase. With each stage bypassed, the resistance in the rotor circuit decreases, allowing the motor to accelerate further. This incremental switching enables a particularly smooth, material-friendly acceleration – a significant advantage for heavy drive loads.

For this task, the robust steel grid fixed resistors from FRIZLEN are particularly well-suited. They are modularly constructed and offer the possibility to combine the required resistance levels in a compact device. We are happy to support you in dimensioning a starting resistor tailored to your application – feel free to contact us, we are here to advise you.

Series T600 | FK 3

Steel grid resistor with continuous power rating up to 66 kW, stepped configuration, in protection class IP00 (optional IP20 or IP23).

Gentle start of DC motors

In industrial settings where a permanent and reliable power supply is essential – for example, for supplying safety-critical components – battery-operated DC motors are often used. A typical application is the lubrication supply for turbines or generators in power plants: Even in the event of a power grid failure, it is crucial that the lubrication continues to run to prevent damage to the equipment. This task is performed by DC motors that are operated via batteries in emergency situations.

When starting such motors, it is essential to limit the starting current in order to prevent overloading of both the battery and the motor winding. For this purpose, single-phase starting resistors are used, which are individually designed for the specific application and power consumption of the motor. By deliberately limiting the current during the starting phase, a smooth start-up can be achieved without excessively stressing the components.

In traditional applications, the resistor is usually short-circuited by a contactor after start-up. However, in safety-critical areas – such as lubricating oil supply in power plants – it may be necessary for safety reasons to dispense with an additional switching device. In such cases, the resistor can be designed to remain permanently in the circuit and work continuously with the motor. This solution minimizes the number of mechanical switching operations and significantly increases system reliability – a clear advantage in safety-critical applications where absolute operational safety is of paramount importance.