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

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...

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...

Over recent years the Lithium Ion battery has become popular in applications requiring high power densities with small weight and footprint.  Today Lithium...

The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with...

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...

When selecting a cable, the performance of the cable under fault conditions is an important consideration. It is important that calculations be carried...

From the earliest times, humans have found ways to create light. Pre-historic peoples used natural materials (moss, grass, etc.) soaked in animal fat and...

In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example.  We then looked at one...

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...