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Technical Articles

How Power Transformer Produces Acoustical Noise?

This technical article explains the acoustic noise generating mechanism inside power transformers. Transformer noise has two sources: winding vibrations and core vibrations. The single most effective way to reduce windings noise… Read more

Dec 05, 2012 | Transformers

How Power Transformer Produces Acoustical Noise?

What Is The Basic Insulation Level (BIL)

Insulation levels are designed to withstand surge voltages, rather than only normal operating voltages. Since the insulation lines and equipment is protected by surge arresters draining the surges rapidly before… Read more

Dec 03, 2012 | Energy and Power

What Is The Basic Insulation Level (BIL)

Arrangements of LV Utility Distribution Networks (2)

Continued from the previous part: Arrangements of LV Utility Distribution Networks (1) In the past, an underground cable service or the wall-mounted insulated conductors from an overhead line service, invariably terminated… Read more

Dec 01, 2012 | Energy and Power

Arrangements of LV Utility Distribution Networks

The Purpose Of Transformer Gas Relay

The transformer gas relay is a protective device installed on the top of oil-filled transformers. It performs two functions. It detects the slow accumulation of gases, providing an alarm after… Read more

Nov 29, 2012 | Protection

The Purpose Of Transformer Gas Relay

How to Predict Life Span of the Switchgear?

The life span of switchgear basically depends on the size of the load and the number of switching cycles. Instead of a time span, with electromechanical switchgear reference is usually… Read more

Nov 28, 2012 | Energy and Power

How to Predict Life Span of the Switchgear?

Inspection and Test Procedures for LV Cables

Visual and Mechanical Inspection Electrical Tests Test Values TABLE 100.12 – US Standard Fasteners – Bolt-Torque Values for Electrical Connections Compare cable data with drawings and specifications. Inspect exposed sections… Read more

Nov 27, 2012 | Cables

Inspection and Test Procedures for LV Cables

Surge Protection for Frequency Converters

In principle a frequency converter consists of a rectifier, a d.c. link converter, an inverter and of the control electronics (Figure 1 above). At the input of the inverter the… Read more

Nov 26, 2012 | Protection

Schematic diagram of a frequency converter

Purpose of Miniature Circuit Breakers (MCBs)

Miniature circuit breakers (MCB) are primarily designed to protect cables and lines against overload (thermal) and short-circuit (electromagnetic). They thus care for protecting this electrical equipment against excessive temperature rises and destruction… Read more

Nov 24, 2012 | Energy and Power

Using Miniature Circuit Breakers (MCB)

HV Instrument Current Transformers in T&D

Electrical measurements on a high-voltage transmission and distribution systems cannot be made practically or safely with direct contact to the power carrying conductors. Instead, the voltages and currents must be… Read more

Nov 23, 2012 | High Voltage

HV Instrument Current Transformers in Transmission and Distribution Systems

VLT Drives in Wastewater Treatment Plant Applications

The most common use of frequency converters is to drive sludge pumps, elevators, conveyers, aeration, chemical dosing, clarifiers, digesters, presses and centrifugal dewatering. In the beginning water is being pumped… Read more

Nov 22, 2012 | Variable Speed Drives

VLT Drives in Wastewater Treatment Plant Applications

Few Words About Frequency Converters

Since the late 1960’s, frequency converters have undergone extremely rapid changes, largely as a result of the development of microprocessor and semi-conductor technologies and their reduction in prices. However, the basic principles of… Read more

Nov 21, 2012 | Industrial Automation

Few Words About Frequency Converters

Wind power applications, Grid connected or not?

There are perhaps four distinct categories of wind power which should be discussed. These are: Small, non-grid connected Small, grid connected Large, non-grid connected Large, grid connected By small, we… Read more

Nov 20, 2012 | Wind Power

Wind power applications, Grid connected or not?

Stator Overheating Protection

All motors need protection against overheating resulting from overload, stalled rotor, or unbalanced stator currents. For complete protection, three-phase motors should have an overload element in each phase. This is… Read more

Nov 19, 2012 | Electric Motor

Stator Overheating Protection


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