From the monthly archives: May 2012

We are pleased to present below all posts archived in 'May 2012'. If you still can't find what you are looking for, try using the search box.

UPS Battery Sizing

By Steven McFadyen on 4/8/2012 1:36 PM

Various techniques exist to enable the correct selection of batteries for UPS applications.  The procedure described below is one of the more common. It is also possible to use the IEEE 485 method ... read more..


Battery Sizing

By Steven McFadyen on 4/8/2012 1:34 PM

This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.

read more..


Introduction to Lighting

By Steven McFadyen on 4/4/2012 1:32 PM

When looking at the design of a lighting scheme it is useful to have an understanding on the nature of light itself and some of the basic theory associated with this.  This article provides an over... read more..


Alternating Current Circuits

By Steven McFadyen on 4/3/2012 1:29 PM

Alternating current (a.c.) is the backbone of modern electrical power distribution. In this article I’ll be pulling some of the more important concepts together. It is a work in progress and I’ll be add... read more..


Electromechanical Relays

By Steven McFadyen on 4/2/2012 10:21 PM

Electromechanical relays have been the traditional backbone of electrical protection systems.  While over recent years these have been replaced by microprocessor based numerical devices, there are ... read more..


Understanding electric motor insulation & temperature

By Steven McFadyen on 4/2/2012 3:01 PM

Anyone specifying or using electric motors should have a basic understanding how the insulation is related to temperature. Three classes of insulation are in common use (with 'F' being the most common).... read more..


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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...

How to Size Power Cable Duct

Some colleagues had an issue earlier in the week on sizing conduits to be cast in concrete for some power cables . It became clear that none of us had...

What is Aircraft Ground Power

Ever wondered what kind of power an aircraft uses when parked at the airport stand. Normally the aircraft generates it own power, but when parked with...

GE's Shingijutsu Factory

GE's latest thinking on product manufacturing is he Shingijutsu philosophy or Lean production system. They have started applying this at the Louisville...

Laplace Transform

Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods...

What are you reading!

Reading is a bit of a hobby of mine and I"ve done a few off-topic posts in the past on this. Rather than continue doing the occasional post I thought ...

DC Motor Operation

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

UPS Battery Sizing

Various techniques exist to enable the correct selection of batteries for UPS applications.  The procedure described below is one of the more common. ...

Lighting - Lamps

Lamps are the essential part of any luminaire. These are the light generating components. Since the advent of electrical lighting in the middle of the...

Electromagnetic Fields - Exposure Limits

Exposure to time varying magnetic fields, from power frequencies to the gigahertz range can have harmful consequences.  A lot of research has been conducted...

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