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WIRING ACCESSORIES AND SINGLE PHASE DISTRIBUTION
PG00400018U – March 2012
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Product overview
Memera consumer units and devices
1.4
Regulations
Relating to
Example
Additional Protection
411.3.3
All socket outlets up to 20A
– Upstairs sockets
30mA RCD
rating for general use by
– Downstairs sockets
ordinary persons
– Kitchen sockets
– Cooker outlet with integral
–
13A socket outlet
– Plus any other sockets rated up to 20A
–
including garage sockets
701.411.3.3
All electrical circuits in a room
– Shower circuit
30mA RCD
with a fixed bath or shower
– Lighting circuit
– Heating circuit
– Ventilation circuit
– Shaver socket
– Socket outlets
522.6.100
All electrical circuits buried in a
All concealed wiring
30mA RCD
522.6.101
wall or partition at less than
– Socket outlets
522.6.103
50mm and without mechanical
– Lighting circuits
protection
– Smoke alarm
– Burglar alarm
In summary
Installation design
The 17th edition wiring regulations BS7671 applies to all new installations designed after 30th June 2008, and there are
various options that must be considered in order to satisfy these requirements. Starting with the wiring scheme and the building design,
consideration must be given to the purpose of the building, and to the persons who will be using the installation, as different regulations
will be applicable, e.g. is the installation under the control of skilled or instructed persons, or ordinary persons, or perhaps the installed
location contains a bath or shower. Answers to these points will start to focus in on the regulations that need to be followed.
Consideration must be given to the way cables will be fitted within the installation, either on the surface in trunking or conduit, or else
concealed beneath the surface of the wall either buried within the plaster or inside the cavity of a hollow partition wall. The chosen
installation methods and wiring accessories or loads being fed, will also dictate whether additional protection by means of 30mA RCDs
is required on those circuits or not.
The wiring regulations are open to interpretation in some areas, where reference is made to “minimise inconvenience in the event of
a fault”, acceptable levels of inconvenience can be somewhat subjective.
In most circumstances the regulations now dictate that a consumer unit will be required to have two or more 30mA RCDs, enabling the
load circuits to be spread over a number of RCD protected zones or outgoing ways.
However, the most comprehensive and effective solution, and one that is guaranteed to fully meet the requirements of the regulations is
to equip each and every circuit with it’s own individual 30mA RCBO.
The examples shown on the next page illustrate just some of the many options available, to a contractor, to achieve a 17th Edition
compliant installation. Some options provide a much higher level of circuit integrity than others. The final choice of which may well be
made based on this and the cost/ease of the installation.