Variable frequency drives are widely used to control the speed of ac motors.  This note looks at the mechanisms which enable drive units to control the...

There are a lot of interesting two page type notes on various medium voltage topics – switchgear, circuit breakers, bus systems etc. It is on the Siemens...

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

IEEE TV has a part series of videos on wind power and it's implication. For a really good overview to the technologies and issues around wind power, these...

The European Union is implementing a voluntary code of practice for participants with the aim of improving the overall efficiency of data centres. As part...

In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...

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...

Depending where in the world you work, you are likely following one of two standards International Electrotechnical Commission (IEC) National...

Often document control is dictated by project requirements, for example a particular organisation may have an existing numbering system. Existing company...

The other day I was talking to a colleague who is a building services consultant.  Despite regularly specifying dry-type/cast resin transformers he was...