From the monthly archives: October 2014

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

What is an Open Delta Transformer

By Steven McFadyen on 10/13/2014 11:54 AM

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 star, resulting in common transformer conf... read more..




Frame Leakage Protection

While not as popular as it once was, frame leakage protection does still have some use in some circumstances.  In essence frame leakage is an earth fault...

Arc Flash Calculations

Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...

How Electrical Circuits Work

If you have no idea how electrical circuits work, or what people mean then they talk about volts and amps, hopefully I can shed a bit light.  I’m intending...

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...

Standard Cable & Wire Sizes

IEC 60228 is the International Electrotechnical Commission's international standard on conductors of insulated cables. Among other things, it defines a...

Cable Insulation Properties

Cable insulation is used to provide electrical separation between conductors of  a cable.  During the historical development of cables, numerous types...

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...

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...

IEC 61439 Verification Methods

The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' has three methods which can be...

Why use catalogues

I'm a fan of using manufacturers catalogues. There are two main reasons for this. Firstly, if your involved in the purchase of equipment, you will likely...

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