We are pleased to present below all posts archived in 'December 2011'. If you still can't find what you are looking for, try using the search box.
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 and controlgear - Part 2: Circuit-breakers] ha... read more..
One of the comments on my Motor Starting Series was asking for something on duty cycles. Here it is.
As a... read more..
Straight forward list of some common motor faults. If I have missed any other common faults, please take a bit of time to add them in as a comment below. read more..
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 I looked under the hood I found cracked cylinde... read more..
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...
The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.
Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...
Most installations involve some form of lightning protection system which is connected to an earth electrode. The function of the earth electrode is to...
For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...
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...
These lifts were first built in 1884 by J. E. Hall and called a paternoster ("Our Father", the first two words of the Lord's Prayer in Latin) due to its...
Anyone specifying or using electric motors should have a basic understanding how the insulation is related to temperature. Three classes of insulation...
From the earliest times, humans have found ways to create light. Pre-historic peoples used natural materials (moss, grass, etc.) soaked in animal fat and...
Electromechanical relays have been the traditional backbone of electrical protection systems. While over recent years these have been replaced by microprocessor...
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