From the monthly archives: July 2012

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

Fault Calculations - Typical Equipment Parameters

By Steven McFadyen on 6/24/2012 7:38 AM

A frequent problem in fault calculations is the obtaining of equipment parameters.  While it is always preferable to use the actual parameters of the equipment, sometimes these are not available... read more..


Low Voltage Fault Tables

By Steven McFadyen on 6/24/2012 7:11 AM

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

read more..


Questions - Reputation and Privilege

By Steven McFadyen on 6/15/2012 9:08 AM

Our question and answer system while letting you do exactly what it says, is much more.  It is a dynamic user driven system, where our users not only ask and answer questions, but can manage the... read more..


Inductance

By Steven McFadyen on 6/3/2012 11:08 AM

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 (measured in weber, Wb). Inductance is the ratio... read more..




Cables for MV Power Distribution - Earthed versus Unearthed Systems

Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...

Fault Calculation - Symmetrical Components

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...

Microsoft OneNote

A couple of months ago I came Microsoft's OneNote and downloaded the 60 day free trail. Since then I have been using it regularly and now have a full license...

myElectrical - Cable Sizing Tool Upgrade

Our IEE cable sizing was wrote a few years ago and had become rough around the edges. I thought it was time to give the tool a service. Unfortunately when...

Understanding electric motor insulation & temperature

Anyone specifying or using electric motors should have a basic understanding how the insulation is related to temperature. Three classes of insulation...

Smarter Electrical Distribution

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

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...

Fire Resistant and Fire Retardant Cables

Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed...

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...

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...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note