 Wire-wound resistors
Application
Wire-would resistors use wire made from special alloys as resistor conductor. Properties like tolerance and temperature coefficient can be adjusted by selecting the appropriate wire and material.
Wire-wound resistors are mainly used for applications in the lower load range up to several kilowatts at low current and/or higher ohm values.
Systems
With the exception of the range of very small loads at low application temperatures, wire-wound resistors are always wound on heat-resistant carriers with insulating properties or embedded in such masses. Very thick wires can also be used without a carrier. The resulting elements are comparable to the designs of cast iron or steel grid resistors (wire grid system AEG).
GINO manufactures and supplies all designs for high-performance resistors starting at about 100 W:
Tube resistors
Tube resistors consist of a wire wound on a ceramic carrier tube. Plain wire is wound on the tube at a specific spacing as resistor conductor. The wire is then embedded in a layer of special concrete, which will fix and protect the wire and ensure good heat distribution. The roughness of the concrete allows for a larger surface and improved cooling. In pulse operation, the concrete will also take on energy.
Alternatively, tubes can also be provided with insulating oxidized wire wound turn to turn. Although this saves the concrete coating, the wire remains unprotected. In case of strong heat formation, the turns will loosen and could slip on top of each other in case of perturbations or rub against each other in case of vibrations, which could damage the oxide layer and result in turn-to-turn fault.
GINO manufactures mainly tube resistors with concrete-coated winding. The concrete coat is annealed in an oven after application and drying which gives a high strength and excellent resistance against high moisture.
Siemens 3PP1 resistors
are air-cooled resistors with cylinder resistors 3PY6. The compact design is particularly suited for intermittent operation in many applications (starting resistors, excitation resistors and field discharge resistors in magnetic control units, braking resistors).
Wire-wound frames
are flat elements with wire windings on ceramic supports at the top and bottom of a carrier frame. The ceramic supports are provided with groves to take on the wire. For ceramic supports without groves, the windings have to be fixed with concrete coating like with the PZ. Due to the uniform design, wire-wound frames are equally suited as system resistors. With a similar design to GINO steel grid resistors, GINO wire-wound frames can be combined with each other and with the steel grid resistors. In this context, a wire-wound frame takes the place of two steel grids.
Wire grids, system AEG
are system elements that match the AEG cast iron resistor system. The elements are resistant to breaking and exhibit a lower temperature coefficient of the electrical resistor than cast iron elements.
Vitreous enameled resistorse
are wire-wound resistors on ceramic tubes whose windings are then coated in a baking oven with a glazing that affords protection against environmental effects.
Wire-wound resistors in aluminum casing
are high-load resistors wound on a ceramic tube and cast into the bore of an aluminum section that takes on the excess heat of the resistor or dissipates it.
Ohm-i resistors
are encapsulated resistors in an aluminum casing with high protection class and non-detachable connection lines, mainly designed for applications requiring high overload capacity and a high protection class.
Standards
The resistor wires used comply with the specifications of DIN 17471, whereby separate standards apply for the alloys. They meet the applicable regulations VDE 0100 and VDE 0660 and conform to the EEC Low Voltage Directive dated 19 February 1973.
Protection classes available
pursuant to DIN 40050/ICE 144, IP00, IP20 and IP23 are available for the 3PP1 units.
Applications
GINO wire-wound resistors are used in the following systems:
Starter switches
Starter switches are starters with air-controlled resistors. The starter steps are switched using contactor-type starters that are controlled via time relay or PLC as a function of the power or speed, and that can be replaced individually in case of a malfunction.
Braking resistors
Braking resistors transform the energy of driven masses by electrically braking the motor propelled by kinetic energy.
Load and testing resistors
Load and testing resistors act as a substitute for the consumer in the presence of energy sources. They are used for testing and for checking batteries, transformers, generators, power generators and power supply units. They can be used to simulate operating conditions to test the performance capacity of energy supply systems.
Grounding resistors
Grounding resistors limit any ground fault current to a maximum admissible value until the corresponding protection facilities have switched off the defective circuit.
Damping resistors
Damping resistors are resistors that have the task to limit the current in a power circuit or prevent inadmissibly high current or voltage peaks. Particularly those resistors used in filter circuits are called damping resistors and are switched in parallel to the reactance coils to dampen them: The resistor takes on the voltage peaks that form in the reactance coil thereby preventing inadmissible voltage surges. It reduces the circuit quality thus resulting in a larger filter bandwidth.
Transport Engineering, train resistors
Particular demands in terms of the electrical and mechanical load carrying capacity and operational safety, low maintenance and long service life are made on resistors for applications in transport engineering.
Text © GINO AG |
|
