Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...

A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This...

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

This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.

This is the first of two posts on the resistance of conductors. In the next post I will look at the ac resistance, including skin effect and we deal with...

American inventor Thomas Alva Edison was born in Milan, Ohio on February 11, 1847. He was the youngest of seven children and received little formal schooling...

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...

How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...

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