Fault Calculation - Symmetrical Components

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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

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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

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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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Magicians of Engineering

The other day I was reading 'Night of the New Magicians' by Mary Pope Osborn with my son.  The story is about a young boy and girl who travel back in time...

Power Factor

Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...

What is an Open Delta Transformer

In three phase systems, the use of transformers with three windings (or legs) per side is common.  These three windings are often connected in delta or...

IEC 60287 Current Capacity of Cables - An Introduction

IEC 60287 "Calculation of the continuous current rating of cables (100% load factor)" is the International Standard which defines the procedures and equations...

Cost Performance and Time

Often us engineers get so bogged down in equations, using software, producing drawings and writing specifications that this becomes the sole focus.   ...

Frame Leakage Protection

While not as popular as it once was, frame leakage protection does still have some use in some circumstances.  In essence frame leakage is an earth fault...

Bows and Arrows

It starts with me reading one of the Horrible History books with my son (Groovy Greeks). Arrows were mentioned which lead to the discussion of the bodkin...

Resistors

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

How to Size Current Transformers

The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...

Michael Faraday (the father of electrical engineering)

Famed English chemist and physicist Michael Faraday was born on September 22, 1791, in Newington Butts, a suburb of Surrey just south of the London Bridge...