From the monthly archives: February 2013

We are pleased to present below all posts archived in 'February 2013'. If you still can't find what you are looking for, try using the search box.

Multimeter

By Steven McFadyen on 2/28/2013 1:04 PM

Multimeters are undoubtedly the most common item of electrical test equipment in use.  Often it is the first piece of equipment people will turn to when trying to visualize and obtain data on an... read more..


IEC 60287 Current Capacity of Cables - Rated Current

By Steven McFadyen on 2/18/2013 5:58 AM

In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example.  We then looked at one method of applying the standard and iden... read more..


Introduction to Current Transformers

By Steven McFadyen on 2/8/2013 11:17 AM

Current transformers (CTs) are used to convert high level currents to a sma... read more..


HTML Symbol Entities

By Steven McFadyen on 2/6/2013 11:45 AM

HTML supports a variety of entity symbols which can be entered using either numbers or an entity name.  The number or name is preceded by the ‘&’ sign and ends in a semi-colon (;).  To ... read more..




How to Size Current Transformers

The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...

The ac resistance of conductors

In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...

Electrical Engineering

Electrical engineering is a field that covers a wide variety of sub-fields, including electricity and electronics. It is a field that goes back to the...

Lighting Design - An Introduction

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...

Equipment Verification (to IEC Standards)

One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment...

How to refer fault levels across a transformer

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

Questions - Reputation and Privilege

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...

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...

Network Theory – Introduction and Review

In electrical engineering, Network Theory is the study of how to solve circuit problems. By analyzing circuits, the engineer looks to determine the various...

Fault Calculation - Per Unit System

Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base.  By removing...

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