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Fault Calculation - Symmetrical Components

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical components, the unbalance system is broken down in to three separate symmetrical systems:...Read More..

By Steven McFadyen on Wednesday, March 27, 2013

Hazardous Areas – IEC and NEC/CEC Comparison

Depending where in the world you work, you are likely following one of two standards International Electrotechnical Commission (IEC) National Electrical Code/Canadian Electrical Code (NEC/CEC) The different nature of the two systems make a direct comparison almost impossible. If you do need to work with......Read More..

By Steven McFadyen on Friday, March 9, 2012

Maxwell's Equations - Gauss's Electric Field Law

Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field. The law was initially formulated by Carl Friedrich Gauss in 1835. In Gauss's law, the electric field is the electrostatic field. The law shows how the electrostatic field behaves and varies depending on the charge......Read More..

By Steven McFadyen on Wednesday, September 4, 2013

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Restricted Earth Fault Protection

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

Differential protection, the good old days

This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...

MIT OpenCourseWare

MIT OpenCourseWare, makes the materials used in teaching all MIT subjects available on the Web, free of charge, to any user in the world.

Voltage Levels – Confused?

I was having a conversation the other day about voltage levels. While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...

Voltage Drop in Installations - Concepts

Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...

What happened to the cable notes?

If you are wondering what happened to our cable notes, the short answer is that we have moved them to myCableEngineering.com. The "Knowledge Base" at...

Generation of a Sine Wave

A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This...

IEC Document Designation

Often document control is dictated by project requirements, for example a particular organisation may have an existing numbering system. Existing company...

Lead Acid Batteries

Lead acid batteries are cost effect and reliable, making them suitable for many applications.This note examines topics of interest associated with the...

Resistors

Resistors are electronic components that oppose the flow of current. Manufactured in various types and ranges they have a wide application to electronics...