The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...

This is the second post in a series of two on periodic electrical inspections. In the first post, I discussed how often inspections should be carried out...

Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...

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

Many medium voltage (MV) indoor switchgear rooms  exist worldwide. The complexity of these rooms varies considerably depending on location, function and...

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...

MIT OpenCourseWare, makes the materials used in teaching all MIT subjects available on the Web, free of charge, to any user in the world.

Our IEE cable sizing was wrote a few years ago and had become rough around the edges. I thought it was time to give the tool a service. Unfortunately when...

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...

Anyone specifying or using electric motors should have a basic understanding how the insulation is related to temperature. Three classes of insulation...