From the monthly archives: August 2009

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

IEC 61439 - The Switchgear Standard

By Steven McFadyen on 7/1/2009 3:08 AM

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 of pre-tested designs. .

Some key... read more..




1,000 kV UHV First for China

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...

GE's Shingijutsu Factory

GE's latest thinking on product manufacturing is he Shingijutsu philosophy or Lean production system. They have started applying this at the Louisville...

DC Component of Asymmetrical Faults

The image (reproduced from IEC 60909) shows a typical fault in an ac system.  From the illustration it can seen that there is an initial dc component ...

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...

Low Voltage Switchroom Design Guide

Low voltage (LV) switchrooms are common across all industries and one of the more common spatial requirements which need to be designed into a project...

What does N+1 mean?

The term 'N+1' relates to redundancy and simply means that if you required 'N' items of equipment for something to work, you would have one additional...

Gas Insulated or Air Insulated Switchgear

Various arguments exist around SF6 Gas Insulated (GIS) and Air Insulated (AIS) medium voltage switchgear. Recently we had to change a GIS design to AI...

Laplace Transform

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

Low Voltage Fault Tables

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

Lighting Design - An Introduction

From the earliest times, humans have found ways to create light. Pre-historic peoples used natural materials (moss, grass, etc.) soaked in animal fat and...

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