Voltage Drop in Installations - Concepts
Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...
Restricted Earth Fault Protection
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...
Paternoster Lifts
These lifts were first built in 1884 by J. E. Hall and called a paternoster ("Our Father", the first two words of the Lord's Prayer in Latin) due to its...
Cost Performance and Time
Often us engineers get so bogged down in equations, using software, producing drawings and writing specifications that this becomes the sole focus. ...
Voltage Levels to IEC 60038
The standard aims to consolidate AC and traction voltages within the industry and defines the following bands:
band 1 - A.C. systems 100 V to 1...
Introduction to Traction Substations
Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...
Nikola Tesla
Nikola Tesla was born exactly at midnight on July 10, 1856 in the tiny village of Smiljan, Lika in Croatia. In his late teens, Tesla left the village to...
Cables for MV Power Distribution - Earthed versus Unearthed Systems
Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...
Lightning Protection and Earth Electrode Resistance
Most installations involve some form of lightning protection system which is connected to an earth electrode. The function of the earth electrode is to...
IEC 61439 - The Switchgear Standard
The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...