Posted on 7/1/2012 10:45 AM By Steven McFadyen
Fault calculations are one of the most common types of calculation carried out during the design and analysis of electrical systems. These calculations involve determining the current flowing through circuit elements during abnormal conditions – short circuits and earth faults.
Posted on 6/24/2012 7:38 AM By Steven McFadyen
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. In this instance it is necessary to resort to the use of typical parameters.
This note is intended to become a collection of typical parameters. If there is something missing or needs adding, please leave a comment in the discussion.
Posted on 6/24/2012 7:11 AM By Steven McFadyen
The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.
Posted on 6/15/2012 9:08 AM By Steven McFadyen
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 way the system works. This is geared around reputation and privileges.
Posted on 6/3/2012 11:08 AM By Steven McFadyen
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 of magnetic flux to current in a circuit. The unit of inductance is the henry, H (Wb/A) and is normally represented by the symbol L.
Posted on 5/29/2012 1:28 PM By Steven McFadyen
Lamps are the essential part of any luminaire. These are the light generating components. Since the advent of electrical lighting in the middle of the 19th century, multiple types of lamps have been developed. Over the years lamp technology continues to evolve offering increases in performance and efficiencies.
Posted on 5/28/2012 2:08 PM By Steven McFadyen
If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive. However, there are a few things which which can life a easier then posting.
Posted on 5/22/2012 8:41 AM By Steven McFadyen
Steel ladders, trays and baskets form the backbone of cable containment systems. Often these items need some form of surface treatment to prevent corrosion due to the installed environmental conditions. The type of surface treatment required depends on the installed environment and corrosive conditions present.
Posted on 5/20/2012 6:14 AM By Steven McFadyen
Our cable sizing tool is one of the more popular tools on the site. The tool enables cables to be sized in compliance with BS 7671 (the IEE Wiring Regulations) and by implication IEC 60364.
This post gives some insight into how the tool works, the calculations carried out and how to use it. With the tool being based on BS 7671, this post will also provide an introduction and explanation of the cable sizing method given in the standard.
Posted on 5/17/2012 12:47 PM By Steven McFadyen
The fundamental component of any analogue computer is the operational amplifier, or op amp. An operational amplifier (often called an op-amp,) is a high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output.
Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices. Many standard IC op-amps cost only a few cents in moderate production volume; however some integrated or hybrid operational amplifiers with special performance specifications may cost significantly more.
Posted on 5/17/2012 11:37 AM By Steven McFadyen
Earthing of electrical systems is essential for the correct functioning and the protecting of life and equipment in the event of faults. The earth electrode (connection of the earthing system to the ground) is an essential part of any system.
The estimation of electrode resistance and functioning during the design stage ensures workable solutions are proposed, enhances the operation and potentially reduces the cost of any installation.
Posted on 5/16/2012 6:02 PM By Steven McFadyen
In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various voltages can currents with exist within the network.
When looking at solving any circuit, a number of methods and theories exist to assist and simplify the process. This post briefly lists some of the more common network theories. For more detailed analysis of any particular theory you can search the myElectrical site or find more information on one of the many other sources available on the web.