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

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

Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed...

Various arguments exist around SF6 Gas Insulated (GIS) and Air Insulated (AIS) medium voltage switchgear. Recently we had to change a GIS design to AI...

Lead acid batteries are cost effect and reliable, making them suitable for many applications.This note examines topics of interest associated with the...

Electrical engineering is a field that covers a wide variety of sub-fields, including electricity and electronics. It is a field that goes back to the...

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

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...

Our cable sizing tool is one of the more popular tools on the site.  The tool enables cables to be sized in compliance with BS 7671 (the IEE Wiring Regulations...

Control theory looks at how systems work and are controlled from a mathematical view.  This note gives a brief introduction to some of the concepts – more...