Fault Calculation - Symmetrical Components

By Steven McFadyen on 3/27/2013 12:52 PM

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 dow... read more..


Hazardous Areas – IEC and NEC/CEC Comparison

By Steven McFadyen on 3/9/2012 11:39 AM

Depending where in the world you work, you are likely following one of two standards

  • International Electrotechnical Commissio... read more..


Maxwell's Equations - Gauss's Electric Field Law

By Steven McFadyen on 9/4/2013 3:47 PM

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'... read more..


Introduction to Current Transformers

By Steven McFadyen on 2/8/2013 11:17 AM

Current transformers (CTs) are used to convert high level currents to a sma... read more..


Dielectric loss in cables

By Steven McFadyen on 11/12/2013 5:19 AM

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes small realignment of weakly bonded mo... read more..


What happened to the cable notes?

By Steven McFadyen on 8/5/2017 3:00 PM

If you are wondering what happe... read more..


Cable Sizing Software

By Steven McFadyen on 10/21/2016 12:31 PM

When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its advantages and disadvantages. read more..


Three Phase Current - Simple Calculation

By Steven McFadyen on 3/1/2009 11:47 AM

The calculation of current in a three phase system has been brought up on our site feedback and is a discussion I seem to get involved in every now and again. While some colleagues prefer to remember... read more..


Motor Efficiency Classification

By Steven McFadyen on 3/28/2012 2:05 PM

Electric motors are one of the most widely used items of electrical equipment. Improving motor efficiency benefits include, reduced power demand, lower operating costs and reduced environment impact.... read more..


Maximum Demand for Buildings

By Steven McFadyen on 6/16/2010 5:42 PM

Estimating maximum demand is a topic frequently discussed. Working out how much power to allow for a building can be very subjective . Allowing too much power results in additional equipment, increased ... read more..


Cable Sheath and Armour Loss

By Steven McFadyen on 10/13/2013 11:44 PM

When sizing cables, the heat generated  by losses within any sheath or armour need to be evaluated. When significant, it becomes a factor to be considered in the sizing of cables.

This ... read more..


Batteries

By Steven McFadyen on 4/8/2012 1:38 PM

A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these are combined in a multitude of ways to produce ... read more..


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Network Theory – Introduction and Review

In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various...

Smarter Electrical Distribution

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

Batteries

A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these...

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...

How to Calculate Motor Starting Time

Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate...

ABB Technical Guides - Motor Operation

ABB has produced a range of technical guides that offer concise explanations of the major technologies and technical issues in low voltage AC drives. ...

Motor Insulation

Insulation on a motor prevents interconnection of windings and the winding to earth.  When looking at motors, it is important to understand how the insulation...

8 Motor parts and common faults

Straight forward list of some common motor faults.  If I have missed any other common faults, please take a bit of time to add them in as a comment below...

Earth Electrode Resistance

Earthing of electrical systems is essential for the correct functioning and the protecting of life and equipment in the event of faults.  The earth electrode...

Induction Motor Equivalent Circuit

Induction motors are frequently used in both industrial and domestic applications.  Within the induction motor, an electrical current in the rotor is induced...

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