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.
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..
This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.
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 (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 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 While over recent years these have been replaced by microprocessor based numerical devices, there are ...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..
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..
Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...
Collection of links to various places with useful motor information. I’ll try and return to the page every now and again to update it with any motor notes...
Electromechanical relays have been the traditional backbone of electrical protection systems. While over recent years these have been replaced by microprocessor...
IEC 60947 is the circuit breaker standard and covers the marking of breakers in detail. Any manufacturer following this standard should comply with the...
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...
Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...
Two driverless and solar power vans have departed from Italy on their way to China via the silk road. During the 13,000 kM trip the vans will drive themselves...
MIT OpenCourseWare, makes the materials used in teaching all MIT subjects available on the Web, free of charge, to any user in the world.
IEC 62305 'Protection against lightning' requires a risk assessment be carried out to determine the characteristics of any lightning protection system...
The image (reproduced from IEC 60909) shows a typical fault in an ac system. From the illustration it can seen that there is an initial dc component ...
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