Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...

GE have put together a time-lapse video shown flight take-off and landings at some airports. An interesting view:

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

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...

I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...

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...

While there are a vast array of cable insulation materials, these are often divided into two general types; Thermoplastic or Thermosetting. For example...

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...

Visitors who like to type web address rather then click menus may be interested in how our URL structure works.

Most installations involve some form of lightning protection system which is connected to an earth electrode.  The function of the earth electrode is to...