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...

This is the second post in a series of two on periodic electrical inspections. In the first post, I discussed how often inspections should be carried out...

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

Lamps are the essential part of any luminaire. These are the light generating components. Since the advent of electrical lighting in the middle of the...

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

If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive.  However, there are...

Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...

A load flow study is the analysis of an electrical network carried out by an electrical engineer. The purpose is to understand how power flows around...

We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below.

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...