A recurring theme on our forums is cable sizing. Now many installations are unique and require special consideration. However, a lot of the time things...

Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base.  By removing...

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...

Fault calculations are one of the most common types of calculation carried out during the design and analysis of electrical systems. These calculations...

I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here. A rectifier transformer is a transformer...

The term 'N+1' relates to redundancy and simply means that if you required 'N' items of equipment for something to work, you would have one additional...

Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...

Most installations involve some form of lightning protection system which is connected to an earth electrode.  The function of the earth electrode is to...

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...