I was having a conversation the other day about voltage levels.  While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...

Electromechanical relays have been the traditional backbone of electrical protection systems.  While over recent years these have been replaced by microprocessor...

One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages.  It is more...

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults. ...

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...

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...

I received this question by email a few weeks. First thoughts was that it is a product of the mathematics of rotating a straight conductor in a magnetic...

Electric motors are one of the most widely used items of electrical equipment. Improving motor efficiency benefits include, reduced power demand, lower...

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...

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...