From the monthly archives: November 2014

We are pleased to present below all posts archived in 'November 2014'. If you still can't find what you are looking for, try using the search box.

Tips for a better Low Voltage Protection Discrimination Study

By Steven McFadyen on 11/3/2014 11:48 AM

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

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Batteries

A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these...

Laplace Transform

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

IEC Reference Designations

The IEC publishes a series of documents and rules governing the preparation of documents, drawings and the referencing of equipment.   Depending on country...

Fault Calculation - Per Unit System

Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base.  By removing...

Large Hadron Collider

The 27 km, Euro 6 billion  Collider lies on the border between France and Switzerland, took nearly 30 years to complete.  Some of the lofty goals for the...

DC Motor Operation

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

Variable Frequency Drive

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...

EU Code of Conduct on Data Centres - Best Practices

The European Union is implementing a voluntary code of practice for participants with the aim of improving the overall efficiency of data centres. As part...

How to Size Current Transformers

The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...

Understanding LV Circuit Breaker Fault Ratings

I think this post is going to be helpful to several of our readers. While the IEC low voltage circuit breaker Standard [IEC 60947-2, Low voltage switchgear...

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