UK’s Leading Engineering Forum For Todays Engineer

Providing Regular Tips & Advice on Variable Speed Drives, Motors & Industry Related Topics

May
18
2017

What protection schemes should be adopted for generators and motors?

Protection schemes // It is difficult to define precisely the protection schemes that should be adopted for an electricity distribution system, given the large number of valid alternatives for each situation, but some schemes will be presented as a guide for protecting the various elements that make up a power system. However, any protection scheme …

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May
11
2017

What is the operating principle of a 3ph induction motor?

Fig. Production of rotating magnetic field in a three phase induction motor. An electric motor converts electrical energy into a mechanical energy which is then supplied to different types of loads. A.C. motors operate on an A.C. supply, and they are classified into synchronous, single phase and 3 phase induction, and special purpose motors. Out …

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May
04
2017

What are harmonics and what do they do?

What are harmonics? The harmonics allow to represent any periodic waveform. In fact, according to Fourier’s theorem, any periodic function of a period T may be represented as a summation of: A sinusoid with the same period T; Some sinusoids with the same frequency as whole multiples of the fundamental; A possible continuous component, if the function …

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Apr
26
2017

Can you advise how to avoid motor failure and prolong their lifespan?

A well and carefully designed motor maintenance program will help to prevent failure and, when correctly used, can be summed up as // Preventive maintenance, Predictive maintenance and Reactive maintenance Inspection cycles depend upon the type of motor and the conditions under which it operates. Motors need maintenance regularly in order to avoid failure and …

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Apr
20
2017

How do you determine motor torque and speed requirements?

The desired speed range may be difficult to achieve depending on the type of application. In general, depending on motor size and load type, very wide ranges may require a special motor. Operation at very low speeds, requiring the motor to run at very low frequency (below approximately 6 Hz) or very high speeds requiring …

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Apr
13
2017

How do capacitors improve the power factor and how do I calculate them?

How to improve the power factor? It’s quite simple. By installing capacitors or capacitor banks. Improving the power factor of an electrical installation consists of giving it the means to “produce” a certain proportion of the reactive energy it consumes itself. There are various different systems for producing reactive energy, including in particular asynchronous compensators …

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Apr
06
2017

What are the installation guidelines for AC power drive systems?

Installation guidelines for AC power drive systems (VSDs and motors) Power drive systems (PDS)// Power drive systems (PDS) are used by a number of various standards. They consist of a Complete Drive Module (CDM) and a motor, together with their interconnections, they do not include driven load. In turn the CDM consists of a Basic …

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Mar
30
2017

What setting parameters are available on softstarters?

Six common setting parameters available on most softstarters// This technical article includes a short description of six common setting parameters available on most softstarters. Other settings may be available depending on the type of softstarter and manufacturer. The setting can be done either by adjusting potentiometers, changing dip switches, using a key pad, a computer or …

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Mar
22
2017

Which is best, an aluminium or copper busbar trunking system?

These two materials (aluminium and copper) are both physically and economically viable for use as conductors in power busbar trunking systems (BTS). Some manufacturers of busbar trunking systems offer a product with copper busbars and others offer a product with aluminium conductors. Increasingly almost all major manufacturers are offering both products, leaving the choice to …

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Mar
16
2017

What is the testing and commissioning procedure for motors?

Scope of Motor Testing// It should be noted that the scope of motor testing depends upon the motor type and size, this being indicated on the inspection forms. Motor vibration shall be measured in a tri-axial direction, i.e.: Point x axis – side of bearing housing at shaft height Point y axis – top of …

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