Drives, motors and switchgear

Specifying, installing, monitoring, controlling, driving and protecting motors and associated machinery.


 

Articles in this Section

Monomer and VOC-free unsaturated polyester resin in modern impregnation machines

The author’s research project compares existing varnish characteristics to those of unsaturated monomer and Volatile Organic Compound (VOC)-free polyester resin.
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Success for first South African girth gear installation

SEW-EURODRIVE South Africa has successfully installed its first girth gear in a rotary kiln at a cement plant currently under construction in Limpopo.
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Grid defection: Cutting Eskom ties

Advances in solar PV technology will soon make the electricity grid an option for many.
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Hybrid curing systems to improve machine resin impregnation efficiency

In modern rotational machine manufacturing plants, production rate, energy efficiency and ease of maintenance must be obtained from each production machine.
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Delivering the latest efficiency standards for power drive systems

How the latest developments in gear motor design benefit the end user.
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Brushless Servo operating principles

The design of a brushless servo motor and drive system in the context of its use in industry.
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70 % savings on power costs with modular energy-saving system

Energy costs can constitute up to 90 % of the lifecycle costs of systems that have not been optimised.
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A bench top motor dynamometer for drive testing

A bench top dynamometer has been developed to allow full testing of a positioning motor
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Power quality meets operational efficiency

The innovative design of a new device series is a technological break-through that provides the perfect Power Quality (PQ) analysis solution.
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Installing and commissioning motors

Expert advice on installing and commissioning of motors and the important aspects that are often forgotten.
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Powering one of the largest floorboard plants in the world

Floorboard production company, Classen, gives credit to the company’s drive partners and automation specialists for Classen’s success at producing 20 more floorboards per minute than any other floorboard plant.
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IEC 61439 - arc fault containment and RAMS

IEC 61439-1 and IEC 61439-2 standards are the subject of many discussions among switchgear manufacturers. Their interpretation is intrinsic to the protection of equipment and people operating in the vicinity of electrical apparatus.
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Energy savings in concrete production

A three-phase permanent magnet motor with two degrees of mechanical freedom was designed to be used in industrial concrete mixers.
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Variable Frequency Drives for conveyor starting

Conveyor belt application is a good example of where the use of Variable Frequency Drives is gaining favour.
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Is Partial Discharge (PD) an issue?

Partial Discharges (PDs) take place in all medium and high voltage machines and equipment, but low voltage motors, operating with electronic adjustable speed systems may also be subjected to Partial Discharge (PD) conditions.
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Motor and drive efficiency – collective approach for better results

Efficiency, reliability and total cost of ownership are terms that are at the forefront of engineering considerations, however, looking at items of equipment on an individual basis may not deliver the maximum benefits.
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Effective, efficient operation of induction motors

Since electric motors account for 70% of the electric power energy generated in industry, it makes good sense to explore different methods to improve efficiency in the consumption of electricity. Variable frequency drives offer methods of improving effici
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High or premium efficiency motors

A high efficiency motor is defined as one that accomplishes more work per unit of electricity consumed than a standard motor. Standard motors are the ones that comply with the minimum efficiency levels regulated for each country.
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Single versus three phase motors with a VSD

Comparing, from a technical and commercial point of view, single phase motors and three phase motors with variable speed drives.
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DTC: A motor control technique for all seasons

Drives that employ innovative direct torque control (DTC) - greatly increase motor torque response.
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Quality of supply in a hydro plant

When the Melbourne Water Cooperation’s network agreement expired, the plant’s impact on the SP AusNet distribution network had to be reviewed.
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Arc-preventative MCCs – safety and protection for personnel and equipment

The guidelines for arc flash prevention and equipment - while intended to help prevent injury and protect equipment - can be confusing.
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Choosing between a soft starter and a VFD to fit your application

A variable frequency drive (VFD) is often more expensive up front, but if it is right for the application, it will provide cost savings in the long run.
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Cut electricity bills on irrigation systems

Actual installations of variable speed drives (VSDs) with high efficient motors at many irrigation systems show average energy savings of 40% and higher.
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Wireless vibration monitoring improves reliability and enhances safety

United Kingdom independent power producer, Barking Power Station, is using a wireless vibration transmitter to monitor rotating equipment remotely and in real time.
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Future of industrial motors: Permanent Magnet

Permanent magnet motors offer a better alternative as the energy efficient machine - and users need to understand their operation to ensure successful application.
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VSDs, the environment and energy efficiency

The interplay between variable speed drives and the environment in the energy efficiency improvement of an electric driven system.
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Comparing slip ring motors with standard ac motors

Replacing slip ring motors with standard ac motors is practical and possible without risk - provided the selection is correctly engineered.
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Electric drives - efficiency: Meanings, definitions, interpretations

Three major means of achieving variable speed control in the industries are mainly mechanical, hydraulic, and electrical/electronic. Each of these control options has its strengths and weaknesses.
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Failure of VSD voltage output waveforms on motors

Improve motor long-term reliability and reduce infant failures – of VSD driven motors.
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Inside a Variable Speed Drive (VSD)

An expert in his field, this author gives an interesting perspective on the intricacies of Variable Frequency Drives (VFDs).
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Accurate measurement capabilities for VSDs

Unique measuring functions make these measuring instruments ideal for analysing the voltage-frequency ratio of pulse-width-modulated variable speed drives.
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Motor repair and rewind - are these viable options?

It has been argued that the motor rewind industry cannot effectively rewind motors and maintain efficiency – and that it is more economical to replace failed motors with new motors.
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Using ac VSDs with squirrel cage induction motors

The use of ac Variable Speed Drives (VSDs) in conjunction with squirrel cage induction motors offers added benefits in terms of the start-up, control and running of mill applications within the mining industry.
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Motor start-up solution creates a more efficient brew

The Carlsberg Brewery in Ashkelon, Israel, has installed a motor start-up solution that enables it to comply with strict utility voltage sustainability requirements.
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Reduce voltage drop when starting large inline motors

Standard induction motors during Direct Online (DOL) start-up can draw as much as seven times the nominal operation current. For larger MV motors, these currents can be quite significant.
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Maximise savings in water pump and waste applications

In water applications, centrifugal pumps are driven by an induction motor directly fed from the network. Flow regulation is accomplished by a few different means.
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Has enough changed in large rotating electrical machines?

In view of Crown Publications celebrating 25 years in the industry in November 2011, the authors ask: How often did motors and generators fail 25 years ago - and how often do they fail now?
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Efficient MG-set driven mine winders

The continued increase in energy costs forces industry to look for ways to improve efficiency. The industry abounds with stories of energy consumption improvement projects that simply fail to deliver the expected return on investment.
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