Monday, January 30, 2012

Extension cable terminations

The following picture shows how the extension cable of a socket outlet extension is terminated to the extension socket units.

Picture 1 – Termination of a house extension cable

(Click in the image to enlarge it)


House appliance: Standard socket outlet extension (This is the type of common socket extension products that you usually see at local supermarkets. It is just a common electrical product.)

Other description:

A house extension cable that you usually see actually has three insulated cables inside it: the LIVE cable, the NEUTRAL cable and the GROUND cable.

Each of the three cables has their own color-coded insulation: Brown for LIVE; Blue for NEUTRAL and Green with yellow stripes for GROUND.

When you work on the connections of these cables, you have to make sure not to connect them in a wrong way.

If you connect in a wrong way, the electrical appliance that takes power from this extension sockets may still work.

For example, you mistakenly swap the connections of the blue and the brown cables.

However, the ON/OFF switches are located at the LIVE connection. Therefore, there is still a voltage going to the appliance connected to the socket.

There are 3 cables coming from the extension cord. So you have three connection points and therefore 3 connection screws.

The connection screw may seem simple enough, but not using it properly has been the cause of many house fires all over the world. See Picture 2 below for a closer view.

Picture 2 – Extension socket wiring connections

(Click on the image to enlarge it)

This is one of the biggest problems with house electrical wiring: the electrical parts look simple enough that everybody thinks they can handle it.

Yes, it is easy. But you must know enough about how the electrical components work to be able to handle it SAFELY.


If you do your own wiring, and you happen to replace an extension cord like one in the picture, make sure the connection of the copper conductor to the termination screw is strong and tight.

If the connection is not tight, then connection surfaces between the copper conductor and the screw present a high resistance to the current flow when the electrical appliance is turned on.

This high resistance will cause a high-energy loss at the connection, which is dissipated in the form of heat.

Over time, if the appliance is in operation long enough, the extension socket unit may overheat and become a source of fire.

A combustible material nearby such as a window curtain, old newspapers, even carpets and rugs may catch fire.

That is how a house electrical fire can get started. It is one of the most common causes also.

Picture 3 – Rear view of the extension socket unit

(Click on the image to enlarge it)

Copyright http://electricalinstallationblog.blogspot.com Extension cable terminations

5 comments:

Dexter Morrison said...

Great! This step by step procedure for electrical installation really helps me to fix wiring problem I had since last week! Thanks, that I was save for calling a electrician!

Madeleine Clark said...
This comment has been removed by the author.
Madeleine Clark said...

Advantageous!Thanks for sharing this guidelines.It's a big help to everyone who wants to procure installation with out calling an electrician.

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hira salman said...

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