Flexibility of household electrical installations is partly necessary because people’s needs change over the time they live in a home, and because houses and flats are sometimes leased or sold. The new occupants want the electrical installation to be adaptable to their needs and wishes as far as possible.
With a strictly conventional electrical installation there is virtually no flexibility. It is usually difficult to add a switch somewhere if you are not prepared to open up the wall, to cut off and install new wiring. However, there are a number of techniques and solutions to overcome this problem, although they must be planned when the system is originally designed.
This white paper is one of a series of thematic white papers covering various aspects of electrical installations in houses, flats and residential units. They are aimed at architects, designers, specification writers, decision makers, installers and students.
1. FLEXIBILITY OF ELECTR
ECI Publication No Cu0241
Available from www.leonardo-energy.org
WHITE
LEXIBILITY OF ELECTRICAL INSTALLATIONS
energy.org
HITE PAPER
ICAL INSTALLATIONS
Guy Kasier
April 2016
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Issue Date: April 2016
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CONTENTS
1. Introduction................................................................................................................................................ 1
2. Sufficient connection points for portable appliances .................................................................................. 1
2.1. Electrical socket-outlets...................................................................................................................................1
2.2. Television connections ....................................................................................................................................3
2.3. Telephone connections ...................................................................................................................................3
2.4. Data connections.............................................................................................................................................4
3. Flexible Socket-Outlets ............................................................................................................................... 4
4. Secondary Distribution Boards.................................................................................................................... 4
5. Structural Measures.................................................................................................................................... 5
6. Electrical Circuits......................................................................................................................................... 5
7. What about Renovations? .......................................................................................................................... 6
8. Useful Links................................................................................................................................................. 7
4. Publication No Cu0241
Issue Date: April 2016
Page 1
1. INTRODUCTION
This white paper is one of a series of thematic white papers covering various aspects of electrical installations
in houses, flats and residential units. They are aimed at architects, designers, specification writers, decision
makers, installers and students.
In this white paper we discuss the flexibility of household electrical installations in more detail. This flexibility is
partly necessary because people’s needs change over the time they live in a home, and because houses and
flats are sometimes leased or sold. The new occupants want the electrical installation to be adaptable to their
needs and wishes as far as possible.
With a strictly conventional electrical installation there is virtually no flexibility. It is usually difficult to add a
switch somewhere if you are not prepared to open up the wall, to cut off and install new wiring. However,
there are a number of techniques and solutions to overcome this problem, although they must be planned
when the system is originally designed.
2. SUFFICIENT CONNECTION POINTS FOR PORTABLE APPLIANCES
One of the main requirements of the home electrical installation is to provide ample socket-outlets for
portable appliances. This primarily applies to electrical socket-outlets but, in a broader sense, it also includes
TV, computer and telephone connections. Let’s begin with the electrical socket-outlets (or “power sockets” as
they are also known).
2.1. ELECTRICAL SOCKET-OUTLETS
Nothing is quite as frustrating as having to live in a home where you are constantly confronted with a shortage
of electrical socket-outlets. As a result, occupants resort to extension cables and trailing extension leads.
Cables are criss-crossed everywhere or sometimes tucked away beneath a rug. The latter can be quite
dangerous because the heat dissipated by the extension cable is trapped, which can lead to overheating. An
adequate number of socket-outlets, thoughtfully installed over the available space, is essential. It’s far better
to have too many power points than not enough.
A few basic rules and tips:
On the floor plan, mark the locations where socket-outlets are definitely necessary for various items
of equipment: kitchen appliances, radio, television, digital recorder, media player, computer, printer,
hard drive, hair dryer, washing machine, dryer, vacuum cleaner, moveable lighting fittings, and so on.
For each of these locations, decide how many devices will be used and then add one or two sockets to
this number.
Install at least one double socket in the corners of each room.
Install a power socket for the vacuum cleaner at the same height as the switch next to the doors
(opposite the hinge side). If the hinge side of a door is located adjacent to a longer section of wall, you
should also install a double socket on this side.
Additional power sockets can be provided every two to three metres on long walls.
In addition to standard 230V power sockets, install a few USB sockets in certain easy-to-reach places.
You can use these to charge your cordless devices (mobile phone, tablet, MP3 player, etc) without a
charger - all you need is a USB cable.
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Figure 1: Now that homes have so many portable devices, there is a greater need for USB charging outlets.
Combination outlets, such as the one shown above, are also available. (Illustration source: Busch-Jaeger)
The location of furniture also needs to be carefully considered as a power socket behind a cabinet is
of little use.
In rooms where television sets will be located, provide sufficient electrical outlets on opposite walls to
give the occupants more choice in deciding where to put the television set.
In an office with a computer, printer and other devices, it is recommended to provide an installation
duct located a little higher than desktop level. The electrical outlets are then readily accessible, and
the duct will allow the addition of extra sockets if required in the future.
The height of the outlets is also important. In the kitchen the general-purpose electrical outlets are
placed 10 to 15 cm above the worktop and other electrical outlets are generally placed 15 to 20 cm
above the finished floor level. However, if you want to build a home that will last for a lifetime, it is
advisable to increase the height to 40 to 50 cm above the floor. This is particularly beneficial for older
people who cannot bend so easily.
For the kitchen appliances, the height and location naturally depend on the kitchen layout and the
kitchen installer should make provision for this in his plans.
Figure 2: This is obviously somewhat exaggerated, but economizing on
electrical outlets in a home is not a good idea. (Illustration source: Fotolia)
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If you need some help deciding on the number of electrical socket outlets and other connection points, many
electrical fittings manufacturers offer a checklist. At the end of this paper there is a link to an independent and
extensive electronic checklist in spreadsheet format.
2.2. TELEVISION CONNECTIONS
Nowadays occupants want to watch television in more than one place. It is therefore important to provide
outlets not only in the living room, but also in the master bedroom, children’s rooms and guest rooms, and
possibly in the kitchen and office.
The specific type of outlet currently depends on the provider and the technology they use (coax cable or
phone line). To ensure flexibility, it is a good idea to provide a phone connection as well as a coax outlet so
that the occupants are always free to choose their preferred provider.
A data outlet should also be provided next to the television connection, because an increasing number of
television sets and digital set-top boxes are being equipped with an Internet port. Some manufacturers have
cleverly responded to this trend with combined coax and data outlets in the same enclosure.
Figure 3: This switch manufacturer launched the combination coax and
data outlet for digital television sets in 2016. (Illustration source: Niko)
2.3. TELEPHONE CONNECTIONS
Even though we all now have smartphones, it is still important to provide outlets for landline phones in the
home, especially for workstations and in offices. However, we also tend to provide telephone connections in
the living room, the kitchen and the bedrooms although the home phone system can be programmed so that
incoming calls at night are not routed to the children’s rooms. In addition to routing outgoing calls and
accepting incoming calls, the home phone system acts as a home paging system, meaning you no longer have
to shout up the stairs to tell the kids that dinner is ready.
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2.4. DATA CONNECTIONS
At home we use Wi-Fi for most of our portable devices. However, it is advisable to provide wired data outlets
for some devices, including computers, network printers, network hard drives, laptops, smart TV, Integrated
Home System, and so on. In one of the next white papers we will discuss the differences between wired and
wireless networks and show that wired networks score better for speed, performance and security.
3. FLEXIBLE SOCKET-OUTLETS
Socket-outlets usually have three wires: two for power and one for earthing, but one or two additional wires
can be installed to increase flexibility. This is very important in installations with remote switches or in
Integrated Home System (IHS) installations. The additional wire or wires then allow the socket-outlet to be
connected and operated by the user. This is particularly useful in situations where you want to connect a
moveable light fitting to a specific power socket. With IHS or remote switches, the light source can then be
incorporated in a so-called lighting mood configuration.
Due to the larger number of wires, it is necessary to use deep flush-mount installation boxes.
Figure 4: An electrical outlet circuit with five wires. The blue and brown wires can
be used to switch or dim specific electrical outlets. (Illustration source: E&D Systems)
4. SECONDARY DISTRIBUTION BOARDS
Conventionally only one distribution board is installed in the home, which means that additional cabling from
the distribution board must be installed for any desired extension. That is not very convenient if the occupants
decide to convert the attic into extra bedrooms, for example. In such situations it is more convenient to have a
separate secondary distribution board on each floor. The supply cables can then be routed from the
distribution board on the same level in the event of an extension, instead of running cables all the way back to
the main distribution board.
The same applies to the kitchen. After a number of years it is quite probable that a new kitchen will be
installed to meet the new or altered needs of the occupants. In most cases the existing sockets for the kitchen
appliances will not be in the right places. To avoid having to run several new cables to the main distribution
board in this situation, it is advisable to provide a secondary distribution board in the kitchen right from the
start. That way the scope of work can be limited to the kitchen, avoiding damage to other rooms or areas for
the installation of additional cabling.
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Figure 5: A flexible design when installing a kitchen leaves all options open for renovations at a later date.
(Illustration source: Dovy)
5. STRUCTURAL MEASURES
There are a number of technical building provisions that can increase the flexibility and lifetime adaptability of
a home. The first of these is a vertical shaft where additional cables can be installed if necessary. This can be
extremely useful when cables have to be run all the way from the roof to the ground floor at a later date
because the occupants want to install solar panels to generate some of their own power.
Providing horizontal shafts is slightly more difficult but it can be done by fitting false ceilings in the hallways to
the various rooms. Any additional cabling can then be installed in the concealed ceiling space, avoiding the
need to run cables through other rooms.
Cellars that extend across the whole property can also increase flexibility, certainly with respect to the ground
floor. You should remember to provide suitable passageways, conduits and/or cables for the garden and
garden shed. And of course you should install a secondary distribution board in the shed.
6. ELECTRICAL CIRCUITS
A fully utilized distribution board provides little or no opportunity for expansion. It is therefore recommended
to provide adequate spare capacity at the time of the initial installation for later expansions on the distribution
board. Usually you should allow for 30% spare capacity.
In certain countries a set number of electrical outlets are allowed per circuit. In that case it is advisable not to
install the maximum number initially so that another socket-outlet can be added to the circuit later on if
necessary.
Several circuits for lighting are also desirable. In larger spaces, such as the living room, it is advisable to
connect the lighting to at least two different circuits, so that the room will not be completely dark if one circuit
fails.
It is better to keep lighting in hallways and staircases separate from lighting in the adjoining rooms. If the
lighting circuit in the bedrooms does not work for some reason, sufficient light can still be taken from the
adjoining hallway.
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7. WHAT ABOUT RENOVATIONS?
In the event of a thorough, total renovation, the answer to this question is easy: you can renovate the entire
installation and update it to provide the same functionality as you would in a new-build home.
In the case of minor renovations or extensions, where it is not desirable to open up the walls and embed new
wiring, you can use plinth systems and installation ducts instead.
Plinth systems are usually installed above existing skirting boards; however, there are also configurations that
can replace the existing skirting boards as the wiring is concealed in the hollow skirting. Matching plinths are
available for vertical sections which, for example, may be placed along a door frame. Small rectangular
channels are also classified as plinth systems. Plinth systems are too compact to accommodate electrical
fittings such as switches and socket-outlets. However, several modules that fit nicely with the plinth are
available for this purpose.
When compared with plinth systems, installation ducts are larger, allowing for all sorts of switch materials to
be installed directly in the duct. They are ideal for mounting directly above a work area, such as a desk,
workbench or kitchen worktop. One of their main advantages is that additional sockets can be installed if
necessary.
All sorts of accessories are available for both plinth systems and installation ducts to give them an attractive
appearance, including flat corners, outside corners, T fittings, end caps, etc. Some plinths and installation ducts
can also be painted to harmonize with the colours and materials of the interior decoration.
Figure 6: Plinths and installation ducts can be used for various purposes. (Illustration source: Legrand)
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8. USEFUL LINKS
Checklist for the electrical installation in the home:
http://www.leonardo-energy.org/checklist-electrical-installation-home
Do you have enough outlets in your home?:
http://pitchbook.copperwire.org/do-you-have-enough-outlets-in-your-home#
USB charging sockets:
http://www.leonardo-energy.org/white-paper/usb-charging-sockets
Are your wall plugs flexible yet?:
http://pitchbook.copperwire.org/are-your-wall-plugs-flexible-yet#
A flexible kitchen installation:
http://pitchbook.copperwire.org/a-flexible-kitchen-installation#
Renovating with plinths and installation ducts:
http://pitchbook.copperwire.org/renovating-with-plinths-and-installation-ducts#