From the monthly archives: November 2014

We are pleased to present below all posts archived in 'November 2014'. If you still can't find what you are looking for, try using the search box.

Tips for a better Low Voltage Protection Discrimination Study

By Steven McFadyen on 11/3/2014 11:48 AM

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults.  The IEC defines discrimination as:

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IEEE Winds of Change

IEEE TV has a part series of videos on wind power and it's implication. For a really good overview to the technologies and issues around wind power, these...

Understanding Motor Duty Rating

One of the comments on my Motor Starting Series was asking for something on duty cycles. Here it is. As a purchaser of a motor, you have responsibility...

Switchboard - Forms of Internal Separation

IEC 61439 'Low-voltage switchgear and controlgear assemblies', specifies standard arrangements of switchboard (call forms of internal separation). The...

Harmonised Cable Codes and Colours

Within Europe the European Committee for Electrotechnical Standardization (CENELEC) has standardised the both the designation and colour of cables.   ...

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...

Back to basics - the Watt (or kW)

When thinking about watts (W) or kilowatt (kW = 1000 W) it can be useful too keep in mind the fundamental ideas behind the unit. Watt is not a pure electrical...

What is LED?

Light Emitting Diodes (LED ) are increasing gaining favour in both the domestic and commercial sectors; due to their efficiency, sustainability and durability...

Differential protection, the good old days

This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...

IEC 61439 - The Switchgear Standard

The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...

Periodic Electrical Installation Inspection – How Often?

How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...

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