If you are working on a large plan, get the real coordinates [latitude, longitude] for two or more points and add them to the drawing. That way you can...

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...

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

IEC 61439 'Low-voltage switchgear and controlgear assemblies', specifies standard arrangements of switchboard (call forms of internal separation). The...

I'm a fan of using manufacturers catalogues. There are two main reasons for this. Firstly, if your involved in the purchase of equipment, you will likely...

Modelica is an open source (free) software language for modelling complex systems. Having never used it before, I thought I would download a development...

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...

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

The International System of Units (abbreviated SI) is the world's most widely used system of units.  The system consists of a set of units and prefixes...

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