From the monthly archives: November 2009

We are pleased to present below all posts archived in 'November 2009'. If you still can't find what you are looking for, try using the search box.

Lightning Protection and Earth Electrode Resistance

By Steven McFadyen on 11/22/2009 7:48 PM

Most installations involve some form of lightning protection system which is connected to an earth electrode.  The function of the earth electrode is to dissipate the lightning strike safely in to ... read more..


1,000 kV UHV First for China

By Steven McFadyen on 11/3/2009 8:33 PM

At the beginning of the year China put the world's first 1,000 kV UHV transmission system into operation. Transmitting power at over a million volts is just amazing.  Some key facts about the syste... read more..




Laplace Transform

Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods...

Switchboard - Forms of Internal Separation

IEC 61439 'Low-voltage switchgear and controlgear assemblies', specifies standard arrangements of switchboard (call forms of internal separation). The...

What is an Open Delta Transformer

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...

Cable Sheath and Armour Loss

When sizing cables, the heat generated  by losses within any sheath or armour need to be evaluated. When significant, it becomes a factor to be considered...

HTML Symbol Entities

HTML supports a variety of entity symbols which can be entered using either numbers or an entity name.  The number or name is preceded by the ‘&’ sign...

Operational Amplifier

The fundamental component of any analogue computer is the operational amplifier, or op amp. An operational amplifier (often called an op-amp,) is a high...

IEC 60287 Current Capacity of Cables - Rated Current

In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example.  We then looked at one...

Motor Efficiency Classification

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

Maxwell's Equations - Gauss's Electric Field Law

Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field.  The law was initially formulated by Carl Friedrich...

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...

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