From the monthly archives: November 2011

We are pleased to present below all posts archived in 'November 2011'. If you still can't find what you are looking for, try using the search box.

How to Size Power Cable Duct

By Steven McFadyen on 11/24/2011 10:09 AM

Some colleagues had an issue earlier in the week on sizing conduits to be cast in concrete for some power cables . It became clear that none of us had a clear idea on an approved method. In the end w... read more..


How to Calculate Motor Starting Time

By Steven McFadyen on 11/15/2011 2:00 PM

Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate this. Failing that, hopefully at least som... read more..


Difference Between Live and Dead Tank Circuit Breakers

By Steven McFadyen on 11/11/2011 10:51 AM

A quick post in connection with an email question:

Live Tank - the circuit breaker the switching unit is located in an insulator bushing which is live at line voltage (or some voltage above g... read more..


How to Size Current Transformers

By Steven McFadyen on 11/7/2011 11:48 AM

The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods exist to size current transformers. This note will... read more..


How to Check a Circuit is Dead

By Steven McFadyen on 11/3/2011 4:46 AM

If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead circuit and finally recheck the live circuit. Carry... read more..




ANSI (IEEE) Protective Device Numbering

The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with...

Lead us, Warleader

Delum, who had watched all in silence, his face empty of expression, now spoke in turn. ' "Lead us, Warleader, into glory."' Reading is something I do...

Maxwell's Equations - Gauss's Electric Field Law

Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field.  The law was initially formulated by Carl Friedrich...

Maxwell's Equations - Introduction

Maxwell's Equations are a set of fundamental relationships, which govern how electric and magnetic fields interact. The equations explain how these fields...

Induction Motor Calculator

Just added a page to the tools, which will allow you to calculate the synchronous speed, slip and rated torque for an induction motor. Not a particularly...

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 measure power supply quality

If your are ever called out to troubleshoot something on your electrical system, one of the first things consider is the supply voltage. You want to ensure...

Low Voltage Circuit Breakers

Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions...

Dielectric loss in cables

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...

Low Voltage Switchroom Design Guide

Low voltage (LV) switchrooms are common across all industries and one of the more common spatial requirements which need to be designed into a project...

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