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 While over recent years these have been replaced by microprocessor based numerical devices, there are ...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..
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...
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...
HTML supports a variety of entity symbols which can be entered using either numbers or an entity name. The number or name is preceded by the ‘&’ sign...
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...
Using software in our work is essential for most of us and we are becoming even more dependant on it's use. While software is a great asset, many times...
Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...
A lot of our members work in countries where PPE (personal protective equipment) is regulated or they work for companies/organizations which take employee...
Many questions sent in to the site are in connection with motor starting and in particular star-delta. For all but the simplest application, there is...
"I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers that might be wrong...
IEC 60287 "Calculation of the continuous current rating of cables (100% load factor)" is the International Standard which defines the procedures and equations...
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