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UNIT 3 COMPONENTS AND ASSEMBLIES

I Describing component shapes and features

1 What do you know about the electrical plugs and sockets used in different countries? In
pairs, describe some specific designs.
2a 3.1 Jan, a project manager for a firm that manufactures electrical plugs and sockets, is
briefing some of his engineering colleagues. Read the briefing and summarise the aim of
the project.

Jan: When you look at the various types of plugs and sockets in different countries, most designs
have a basic layout that’s existed for decades, in terms of the way the pins are laid out, and the
profile of the pins. And as a manufacturer, the position of our company has always been,
basically, to accept that we're stuck with several standard configurations, and to effectively say
to customers, we produce all the main formats - take whichever one you want. However, as I’m
sure you know, many countries use plugs and sockets of more than one format. And this leads to
a comparative situation, with some configurations becoming more popular, and others
progressively being abandoned. This is particularly true in countries undergoing rapid economic
expansion. And because of this process of selection, we’re finding that big customers are
increasingly asking us which of the standard plug and socket formats in current use we
recommend as a manufacturer. Which are the best from a technical standpoint? Up until now,
we haven't had a standardised company policy to allow us to respond to that question properly.
But this project aims to formulate a company policy that allows us to say these are the
configurations we recommend, and these are the technical reasons why we recommend them.

b In pairs, discuss what is meant by profile of the pins and standard configuration.
c 3.2 Erin, an engineer with the same company, is describing different electrical plug and
socket formats during the briefing. Listen and match the descriptions (1-6) to the pictures
(a-f).

1
Erin: On this one, there are circular pins for live and neutral. There's no earth pin. This is quite
a common format in Europe and Russia. It's also quite widely used in India.
2
Erin: Here, you’ve got circular slots for live and neutral. And the earth slot’s got a flat base
with one side rounded over to form a semi-circle. This type’s only used in a few places.
3
Erin: This one has rectangular blades for live, neutral and earth, in triangular configuration.
This is the standard in the UK and Ireland, and a few other places, Malaysia and Singapore, for
instance.
4
Erin: This plug has got circular pins for live and neutral, and it has a cylindrical slot to receive
the earth pin. It’s quite common in continental Europe, and in parts of Africa.
5
Erin: As you can see, there are circular pins for live, neutral and earth, and the pins are
arranged in linear configuration. This is not a very commonly used format.
6
Erin: This is the standard in North America, and quite common in Central and South America.
Used in Japan, as well. There are flat blades for live and neutral, and a round pin for earth, and
they’re laid out in triangular configuration. So, an extremely widely used format.

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