From the monthly archives: December 2012

We are pleased to present below all posts archived in 'December 2012'. If you still can't find what you are looking for, try using the search box.

Understanding Circuit Breaker Markings

By Steven McFadyen on 12/12/2012 1:26 PM

IEC 60947 is the circuit breaker standard and covers the marking of breakers in detail. Any manufacturer following this standard should comply with the markings. read more..




Inductance

When current flows within a wire, a magnetic field is created. The potion of this magnetic field perpendicular to the wire is called the magnetic flux...

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...

Calculating Cable Fault Ratings

When selecting a cable, the performance of the cable under fault conditions is an important consideration. It is important that calculations be carried...

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...

Electromagnetic Fields - Exposure Limits

Exposure to time varying magnetic fields, from power frequencies to the gigahertz range can have harmful consequences.  A lot of research has been conducted...

Control Theory

Control theory looks at how systems work and are controlled from a mathematical view.  This note gives a brief introduction to some of the concepts – more...

Voltage Levels – Confused?

I was having a conversation the other day about voltage levels.  While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...

3 Phase Loads

Three phase systems are derived from three separate windings, either connected in delta or star (wye). Each winding can be treated separately, leading...

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...

Occam's Razor

I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...

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