In-House Production

Dynamic Braking Resistors

“Invertor braking resistors” are used in order to ensure fast stopping or decrease the speed of AC and DC electric motors controlled by speed drives (speed control devices).

Due to kinetic energy, an electric motor continues to rotate for a short time even after it has been switched off. As the rotor keeps rotating, the motor starts acting as a generator and feeding the drive. This may not only increase the stopping time of the motor, but also cause a voltage increase on DC drive’s terminal leading to an overvoltage fault and consequently a shut down.

In order to avoid such problems, a breaking resistor of a proper resistance value and rated power should be connected to the DC drive’s terminal.

Applications:

Braking Resistors are used in many motor applications that is controlled with driver.

  • Vertical and horizontal movements of fixed cranes, portal bridge cranes, overhead travelling cranes and tower cranes
  • Travelling facade platforms used for construction and maintenance of buildings, facade hoists and personnel elevators, cradle systems and facade cleaning systems
  • Lifts and elevators controlled by a driver and operated by a synchronous (geared) and asynchronous (gearless) motors
  • DC and AC servo motor drives used in robot control, digital control and position controller automation systems
  • Vertical or angular movement systems such as conveyors or loaders
  • Mixing, crushing and drum applications at mines
  • Reel applications at cable, wire or textile manufacturing plants
  • Factory doors controlled by motor drives
  • Machinery and presses where heavy loads are moved instantly
  • Railway vehicles and hybrid or electrical road vehicles
  • Wind turbines

Determination of Power and Resistance values of Braking Resistor:

Resistance value of the braking resistor changes based on the drive. This can be detected by the driver's manufacturer. This value is specified in the drive's user guide. If this value is given as Rmin and Rmax, the resistance should be close to Rmin and but not lower than Rmin. Braking time extends as it gets closer to Rmax.

The resistance power is determined based on the application used by the motor to which the drive is connected. It can be determined with special engineering calculations or specified by the company based on our experience on frequently used applications. In some cases, the power of resistance can be equal to the motor power, or even up to ten times smaller than it.

Braking resistors are classified in two groups based on the type of cabinet.

1- Aluminum-Case Braking Resistors:

The resistor made of stainless steel wire is placed in an aluminum case with a larger surface which allows good heat dissipation. The space between the resistor and the case is filled with a material which have high thermal conductivity and electrical insulation. Resistors manufactured using this technology can be used as braking resistors or capacitor discharge resistors, constant load tester, wind power plants, hybrid vehicles and other industrial applications.

Standard resistors are 1-meter long, with fiber glass braided silicone cables suitable to rated current and cable connections resistant to high temperature. They can be manufactured with connectors or terminals on request.

Technical Specifications:
Maximum operating voltage 1000 V
Resistance tolerance (@ 20°C) ± %5
Koruma Sınıfı IP5X
Insulation 2kV, 50/60Hz, 1min

Advantages:
  • Compact sizing, option to use without a cabinet, elegant design.
  • High protection degree agains to humidity, dust, solvents and water splash
  • Excellent mechanical impact and vibration withstand.
  • Efficient design to ensure long useful life with an internal structure with high heat transmission and external structure facilitating heat transmission

2- Frame Resistors

The resistor element is in open space and therefore these braking resistors are used inside an enclosure .

“Spring Resistor”, “Edge-Wound Resistor” and “Grid (Plate) Resistor” types are used on frame resistors.. This resistor elements are mounted inside our standard frames in serial or parallel connections. The cross-section of the wire or the grid, loading or release of the spring and parallel or serial connections are calculated by engineering software.

Frame Resistors are classified in 4 standard groups

  • K-series,
  • P-series,
  • E-series,
  • G-series,

K-Series Frame Resistors

Spring type resistor elements are used inside K-Series frame resistors. this type is perfectly suitable for short-time overloads due to its spiral form. Heated wire absorb any expansion thanks to spiral form and gets back to its colder form. With this feature, the spring resistor ensures safety and a long operating life for especially the braking resistors.

Technical Specifications:
Maximum operating voltage 1000 V
Resistance tolerance (@ 20°C) ± %5
Protection class (internal applications) IP20
Insulation 3kV, 50/60Hz, 1min
Frame Material Galvanized steel

Advantages:
  • To ensure protection degree from all direction, the bottom part of the frame is also closed and ventilated.
  • All connections are made with electric terminal. All terminals are inside a junction box with an easy-to-remove cover.
  • Cable entries are with a waterproof brass gland.
  • Resistors are connected to the connector with a thick copper wire covered by a silicon tube or silicon glass fiber cables resistant to heat.
  • All connection elements are manufactured of non-corrosive material.
  • Our frames are designed with special connector - junction box system. Our frames have a unique quality both visually elegant design and with friendly usage and safety.

P-Series Frame Resistors

“Aktif” prefer to use stainless steel frames for outdoor application instead of painted frames. P-Series resistors are suitable for outdoor use of our K Series resistors.

Technical Specifications:
Maximum operating voltage 1000 V
Resistance tolerance (@ 20°C) ± %5
Protection class (external applications) IP23
Insulation 3kV, 50/60Hz, 1min
Frame Material Stainless steel

Advantages:
  • To ensure protection degree from all direction, the bottom part of the frame is also closed and ventilated.
  • All connections made with electric terminal. All terminals are inside an aluminum (IP65) junction box with an easy-to-remove cover.
  • Cable entries are with a waterproof brass gland.
  • Resistors are connected to the connector with a thick copper wire covered by a silicon tube or silicon glass fiber cables resistant to heat.
  • All connection elements are manufactured of non-corrosive material.
  • Our frames are designed with special connector - junction box system. Our frames have a unique quality both visually elegant design and with friendly usage and safety

E-Series Frame Resistors

Edgewound resistors are used for E-series frame resistors. Edgewound resistor type, the resistor element is in the form of stainless steel stripe plate. This stripe plate is wound on an electro-ceramic frame vertically. Large cross-section and the capability of fast cooling offers an optimal solution for high power - low resistance braking resistors.

Technical Specifications:
Maximum operating voltage 1000 V
Resistance tolerance (@ 20°C) ± %5
Protection class IP23
Insulation 3kV, 50/60Hz, 1min
Frame material (Outdoor) Stainless steel
Frame material (Indoor) Galvanized steel

Advantages:
  • Compact and elegant frames with a high cooling performance are specially designed for high power loads.
  • Available for transport with forklifts and lifting lugs at the roof.
  • All connector elements are manufactured of non-corrosive materials.
  • All terminals are inside an aluminum (IP65) junction box with an easy-to-remove cover. Cable entries are with a waterproof brass gland.
  • High-quality resistance materials resistant to corrosion and extreme environmental conditions.
  • Special structure resistant to fast cooling, overloads and electrical forces.

G-Series Frame Resistors

G series braking resistors are manufactured in blocks by connecting in series or in parallel with the desired power and resistance value by the stainless steel grid type resistors specially designed according to the desired current density. They are generally used for high power and low resistance applicaitons.

Technical Specifications:
Maximum operating voltage 1000 V
Resistance tolerance (@ 20°C) ± %5
Protection class IP23
Insulation 3kV, 50/60Hz, 1min
Frame material (Outdoor) Stainless steel
Cabinet material (Indoor) Galvanized sheet

Advantages:
  • Compact and elegant frames with a high cooling performance are specially designed for high power loads.
  • Available for transport with forklifts and lifting at the roof.
  • All connector elements are manufactured of non-corrosive materials.
  • All terminals are inside an aluminum (IP65) junction box with an easy-to-remove cover. Cable entries are with a waterproof brass gland.
  • High-quality resistance materials resistant to corrosion and extreme environmental conditions.
  • Special structure resistant to fast cooling, overloads and electrical forces.

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