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STARBREAKER CONSUMER UNITS
AND THE 17th EDITION
Under the 17th edition wiring regulations (Published in January 2008) the following will apply to
all domestic and residential installations.
SOCKET CIRCUITS 411.3.3
RCDs are now required to provide additional protection. To be recognised
as providing additional protection the RCD must be rated at 30mA or less
and operate within 40ms when tested at 5x operating current.
!
RCDs are now required for all general use socket outlets rated
up to 20A.
Two exceptions are allowed for;
1.
Socket outlets used under supervision of skilled or instructed persons.
2.
A socket outlet suitably identified for connection of a particular item
of equipment.
CABLES 522.6.
101
, 522.6.
102
Regulation 522.6.
101
A cable concealed in a wall or partition at less than 50mm from the
surface shall:
1.
Incorporate an earthed metallic covering suitable for service as the
circuit CPC-
or
2.
Be enclosed in earthed conduit
or
3.
Be enclosed in earthed trunking or ducting
or
4.
Be mechanically protected against damage from penetration by nails
or screws and the like
or
5.
Be installed in the prescribed zones.
Regulation 522.6.
102
Where 522.6.
101
applies and the installation is
not
intended
to be under the supervision of skilled or
instructed
persons,
cables
installed
in
accordance
with
522.6.
101
(5)
but
not
having
mechanical
protection
of 1,2,3 or 4 shall
be
provided
with
additional
protection by means of a 30mA RCD.
Bathrooms
!
Section 7
Special Installations or Locations.
!
Section 701
Locations containing a bath or shower.
!
Zone 3 has been removed.
!
Suitable equipment can be within 600mm of a bath, excluding 13A
sockets to BS1363 which must be 3m from the edge of a bath or
shower.
!
Additional protection shall be provided by the use of
one or more
residual current device
with a rated operating current not
exceeding 30mA (701.411.3.3).
!
Supplementary bonding is not required so long as any Protective
Equipotential Bonding has been installed (411.3.1.2).
Additional protection must be provided in the event of failure of the
provision of basic protection and/or the provision of fault protection or
carelessness by users of the installation.
Protection by 30mA RCD will
be required for;
!
Upstairs ring circuit
!
Downstairs ring circuit
!
Kitchen ring circuit
!
Cooker control unit c/w socket outlet
In the majority of domestic situations cables installed beneath a plaster
surface within partition walls without mechanical protection will require
additional protection by
30
mA RCD regardless
of their routing.
!
Upstairs lighting
!
Downstairs lighting
!
Immersion heater
!
Smoke alarm
!
Burglar alarm
Additional protection must be provided by
one or more 30mA RCDs.
!
Shower circuit
!
Lighting circuit
!
Heating circuit
!
Ventilation circuit
Chapter 31
314.1
Requires that; Every installation shall be divided into circuits, as necessary, to:
i.
Avoid danger and minimize inconvenience in the event of a fault
ii.
Facilitate safe inspection, testing and maintenance
iii.
Take account of danger that may arise from the failure of a single circuit such as a lighting circuit
iv.
Reduce the possibility of unwanted tripping of residual current devices (RCDs) due to excessive protective conductor
currents produced by equipment in normal operation.
Consideration
Consideration for appropriate circuit division has never been greater.
Specific reference is made within the new standard to taking account of and reducing possibilities of
danger and inconvenience arising from the failure of a single circuit such as a lighting circuit. For example;
the result of an RCD operating due to a fault at the shower should not create a low light hazard in the bathroom.
Some circuits may require independence from a shared RCD but their installation method may still
dictate 30mA RCD protection. Examples may be smoke alarms, burglar alarms, door entry systems.
British Standards and IEE regulations are subject to change and amendment. This guide to Crabtree
consumer units is not a substitute for the regulations which should always be used for all types of electrical
installation design, and installation work.