Title:
Maintenance of Electrical Equipment
Code of Practice
Originator:
Approved by:
Date: 16 October 2002
College Safety Officer Principal
Reviewed: July 2014
Next review: July 2016
Notes: This is an amended code of practice issued under the terms of the
College Health, Safety & Welfare Policy.
Scope
This Code of Practice deals with the safety precautions and maintenance
routines necessary to ensure the continued safe operation of all portable
electrical equipment, extension leads, supply sockets and plugs within the
college environment and as such forms part of the College Health, Safety &
Welfare at Work Policy.
This Code of Practice does not cover any of the equipment or plant which is
maintained by Estates Management as part of any maintenance agreement
nor does it deal with the maintenance of the fixed electrical installation.
Definitions
Portable electrical equipment - any electrical equipment that utilises a
13Amp plug.
Group “A” - Hand held or operated whilst connected to the supply.
Group “B” - All other items connected via 13Amp plug but excluding
Group “C & D”.
Group “C” - Business Equipment.
Group “D” - Low Voltage Equipment e.g. below 50 volts.
Fixed electrical equipment - any electrical equipment that is permanently
wired into the mains supply.
Business Equipment – any electrical equipment used within a classroom or
office environment, (e.g. Computers, FAX, Telephones, Modems, Answer
M/C, Scanners, Printers, Photocopiers etc,) which are connected to 240 volt
mains services and not frequently moved.
Low Voltage Equipment – any electrical equipment which operates via a low
voltage supply including plug-in transformer units (e.g. below 50 volts).
Competent - having sufficient knowledge and understanding to undertake
the task safely.
Roles and responsibilities
The Board of Governors shall have a duty to ensure that the measures
detailed with this Code of Practice are adequately and appropriately
supported.
Managers are required to implement this Code of Practice in accordance
with the terms of the College Health, Safety and Welfare at Work Policy.
The Technical Support & Resources Manager is responsible for ensuring
staff undertaking electrical safety checking of equipment are adequately
trained.
1 Electrical installation
1.1 All electrical services must comply with the current requirements as
detailed in the Electricity at Work Regulations 1989 and the
Institution of Electrical Engineers Wiring Regulations (BS 7671). All
fixed equipment must also be installed in accordance with the IEE
Regulations by a competent, suitably qualified person.
1.2
Under no circumstances must any changes be made to the fixed
electrical installation, whether permanent or temporary, without
proper authorisation from the Head of Estates, who will arrange for
any necessary work to be undertaken on behalf of the College.
2 Apparatus
2.1 Most of the electrical equipment used within the College will be of the
normal domestic or commercial pattern and as such will comply with
the Electrical Equipment (Safety) Regulations 1994 or the current
British/EU Standard applicable to that particular item of equipment
and should, therefore, be safe in normal use.
2.2
Staff responsible for the acquisition and purchase of electrical
equipment for use within the College must ensure that all electrical
equipment purchased for College use meets either the applicable
British/EU Standard or some other nationally recognised standard
before completing the purchase arrangements, if any doubt exists
then the College Safety Office must be consulted.
2.3
No privately owned electrical equipment may be used on College
premises without written authority from your Manager
. This authority must be renewed annually. All such equipment and any
electrical equipment made for a special purpose must be tested for
electrical safety by a competent person before it is first used.
2.4
All Curriculum and Business Support Areas shall maintain a complete
inventory of electrical equipment and extension leads purchased or
acquired for use in the College and each item shall be identified by
either a serial number or some other easily identifiable unique mark.
2.5
Managers shall make arrangements to ensure that all electrical
equipment held in the Area is subject to a routine test and inspection
in accordance with the attached schedule (Appendix 1a). Whilst the
schedule gives greater flexibility, all electrical items shall be inspected
at least every three years and where necessary, more frequently as
determined by the risk assessment, and the results of these tests
recorded in a register designed for that purpose.
2.6
All portable electrical apparatus and extension leads shall be visually
inspected and electrically tested using a Portable Appliance Tester
(PAT) or some other method approved by the College Safety Officer,
initially in accordance with Appendix 1a. Any defects found must be
rectified by a competent, suitably qualified person before the
equipment is used again, and any defective equipment must be
effectively made safe or disposed of safely.
2.7
Appendix 1, shows a typical list of routine electrical and visual checks
which can be carried out by suitably trained people.
3 Flexible cables
3.1 Defective plugs, sockets, leads and other accessories cause more
electrical accidents than the appliances with which they are used.
Such defects may for example result in external metalwork of an
appliance, which is normally earthed and safe to handle, becoming
live at a dangerous voltage.
3.2
The three core flexible cables used on domestic and most commercial
appliances have the following conductor insulation colour coding by
international agreement:Live or Phase conductor
- Brown
Neutral conductor
- Blue
Earth of Protective conductor - Green and Yellow
3.3
It is important that any mains plug which is attached to an electrical
appliance is both wired and fused correctly and that the cable is held
firmly in the cable grip. No person should attempt to fit a mains plug
unless they feel competent to do so and have received training if
required.
3.4
The flexibility of flexible cables is achieved by making each conductor
from a number of fine wires, usually of annealed copper. Insulation is
used to prevent contact with the conductor and to minimise electrical
leakage between conductors and earth. The insulating covering used
on flexible cables is not thick or strong enough on its own to provide
complete physical protection and it is often necessary to provide an
additional covering of a tougher material.
3.5
Screened and armoured flexible cables may be used where the extra
physical protection is required but these must be properly terminated
and earthed in accordance with the manufacturer’s instructions.
Armoured cables should only be terminated in purpose-made cable
clamps, preferably made to BS 6121 or BS 4121. The fitting of such
terminations is a skilled operation and should only be carried out by
someone who is competent.
3.6
Repeated flexing of cables will eventually cause the conductor to
fracture and the sheath to crack. The damage usually occurs first at
the terminations where the cable enters an accessory or apparatus, at
the cord grip or gland. The damage is usually apparent at the
periodic maintenance check when the cable should be replaced before
a dangerous fault develops such as exposure of the conductors.
Damage of this type can be reduced by the fitting of a resilient sleeve
through which the cable is threaded. Sleeves which are made of
tough rubber or plastic are recommended but not those made of
sprung metal as they will damage the cable and are unlikely to be
earthed and could therefore become live.
3.7
Some portable equipment is capable of causing damage to the
sheath, or even to the insulation, of its own flexible lead. In such
cases the lead should be secured in such a way that it cannot come
into contact with moving or hot parts. Staff and students who use
such equipment should be made aware of this hazard and of the
methods used to avoid such damage.
3.8
Flexible cables, which have become damaged, must be replaced and
not repaired. However, where a long cable is damaged in one place
but otherwise remains serviceable, the damaged part may be cut out
and a proprietary cable coupler used to repair the cable. If a coupler
is used, the female connector must be on the supply side and the
male plug on the cable connected to the apparatus side. The use of
insulation tape as a temporary repair medium on flexible
cables is not permitted.
4 Plugs and sockets
4.1 Only plugs and sockets which comply with 'The Plugs and Sockets etc.
(Safety) Regulations 1994', made to the appropriate British, CE or
ASTI Standard may be used within the College premises or on College
owned equipment. The normal BS 1363A,13 Amp flat pin type plug
with part insulated pins made by MK is the type recommended for
use, and this must be fitted with a cartridge fuse to suit the size of
cable and the current rating of the equipment to which it is attached.
4.2
A 13 Amp fuse for equipment drawing a low current is dangerous, and
in the event of an electrical fault arising, may damage the equipment
or start a fire. It is a good idea to mark the fuse rating on the
underside of the plug for future reference.
Common fuse sizes and their ratings;
3 Amp fuse is suitable for equipment up to 720 watts i.e.
Radios, Record Players, Tape Recorders, Fridge’s.
5 Amp fuse is suitable for equipment between 720 to 1200
watts i.e. Televisions, Small Irons, Food Mixers, Small Power
Tools.
10 Amp fuse is suitable for equipment between 1200 to 2400
watts i.e. Small kettle, 2 Bar Fire, Large Power Tools.
13 Amp fuse is suitable for equipment between 2300 to 3000
watts i.e. 3 Pt Kettle, 3 Bar Fire, Fan Heaters.
In general terms if equipment requires more than 12 Amps supply
then consideration should be given to direct wiring via a fused outlet
as normal mains plugs will get quite hot if continually operated at this
current level.
4.3
The use of adaptors is not permitted within the College
premises, but purpose made, fused multiple socket outlet assembly
units are permitted when there is a temporary requirement for more
socket outlets provided the total load does not exceed 12 Amps. The
use of extension leads as a semi-permanent method of supply
or the use of extension leads connected to other extension
leads, is considered hazardous and should therefore be firmly
discouraged.
4.4
The use of other plug-in devices such as timers, residual current
devices and transformers is permitted, but these should be carefully
chosen to ensure their weight and leverage does not lead to undue
mechanical stress on the supply socket. The College Health Safety
Office or Head of Estates should be consulted if there is any doubt.
4.5
Plug cord grips must be fully operational and must be checked at the
same time as the electrical tests are carried out. If the cord grip
should fail, the pull of the cable is taken by the terminals. The earth
terminal is the furthest away from the cable entry point and, unless
the plug is wired up carefully, the earth protective conductor is the
first to take the strain and is pulled out of its terminal. The earth
terminal is close to the live terminal and to the fuse carrier and a
loose earth wire can come into contact with these live parts with the
result that the apparatus metalwork will become live.
4.6
Plugs made of resilient material typical of those which claim to be
drop-proof or weatherproof should be treated with caution as some
have been found to be too resilient and can be inserted into sockets
for which they are not designed.
5 Maintenance of flexible leads and plugs
5.1 Flexible leads, plugs and sockets will deteriorate in service, so regular
maintenance is essential to ensure user safety. Routine inspections
should be made by someone who is capable of recognising faults and
defects which should then be repaired by an electrician or other
competent person
5.2
Cables fitted to some equipment are particularly vulnerable to
damage and wear because of the equipment itself or because of the
location in which it is used (eg workshops). Enclosure, plugs etc
should be checked and maintained as part of the portable appliance of
which they form part, but damaged leads, plugs etc must not be
allowed to remain in service just because the appliance itself is not
due for maintenance.
5.3
Extension leads which are not part of other electrical equipment
should have an identifying mark so that these items are not
overlooked during the routine inspections, and each item of
equipment or extension lead shall be marked with a label which states
the date when the equipment was last tested or a date when it should
be retested. This date should also be recorded in the equipment
record sheet (see Appendix 2).
5.4
Maintenance periods will vary for each item of equipment depending
upon the degree of use and the environment etc, but every item of
electrical equipment and every extension lead should be tested and
inspected before first being used and at least every three years
thereafter.
5.5
Residual current devices (RCDs), otherwise known as earth-leakage
breakers (ELCBs), are fitted to some items of equipment and also in
most laboratory areas. Every RCD unit has a test button and this
should be used routinely to check the operation of the RCD and to
free the mechanism of any friction. It is recommended that all RCDs
in regular use are tested in this way at least every month and those
which are fitted to high risk equipment, such as water cleaners, are
tested each time the equipment is used.
5.6
A routine schedule of testing for RCD's shall be established by the
Head of Estates who will ensure that all RCD units (installed as part of
the fixed installation) are checked and tested once a year using the
approved test equipment. Portable RCD units must also be tested in
this manner and Managers s are advised to make arrangements with
the Head of Estates to ensure that these tests are carried out at least
once per year.
5.7
Any defects which are discovered in the fixed electrical installation,
i.e. the socket outlets, power isolators, light switches or fittings, RCD
units etc, should be reported to Estates Management immediately in
writing and where necessary measures taken to prevent any
foreseeable injury occurring.
6 Operation of apparatus outside normal hours
6.1 The unattended operation of experimental apparatus outside normal
working hours poses a potential health and safety risk to security
staff, cleaners, caretakers and other people who use the building and
to members of the emergency services who may be called upon to
attend an incident on our premises.
6.2
Managers must recognise this potential hazard and introduce systems
of work which counteract the risk and provide a safe working
environment. The system recommended is one which uses the
'overnight running authorisation system' as described in the
Education Service Advisory Committee guidance circular 150/86 and
reproduced here.
This guidance applies to:
(a)
Apparatus and rigs but not proprietary equipment such as
refrigerators, drying ovens, spectrometers, etc.
(b) Use of apparatus outside normal working hours including
overnight, weekends and holidays.
(c)
Those wishing to leave apparatus unattended including
research students, their supervisors, academics, technicians
etc.
6.3
Operation
6.3.1 The flow chart (Appendix 3) gives a stage breakdown of how a
safe system can operate. Those responsible for the apparatus
should decide how to operate and maintain it safely. The
design should ensure that any failure of the equipment or the
services to it results in the apparatus shutting down safely (fail
to safety mode).
6.3.2 Managers may wish to provide written guidance on safety
standards, including information on the safe provision of:
(a)
Water cooling systems;
(b)
Means to heat the apparatus;
(c)
Electrical connections, particularly with reference to
the ingress of water or solvents;
(d)
Fire-fighting equipment;
(e)
Means to isolate the apparatus in an emergency.
6.3.3 In order that such a system is effective the authorisation
given by the Manager should:
(a)
Give the precise location of the apparatus to which
it refers;
(b)
Have a finite duration;
(c)
List the services used;
(d) Indicate where they may be safely isolated;
(e)
Give precise instructions on what to do in an
emergency;
(f)
Give emergency contacts.
6.3.4 Authorisation should be numbered and distributed to all
those who need to know about the existence of unattended
apparatus such as Caretakers, Technicians, Admin Office, etc
and copies should also be displayed on or near to the
apparatus. (A suggested form is shown in Appendix 4).
6.3.5 The authorisation should be countersigned by the
Manager or appropriate Manager, who should check that the
appropriate safeguards are incorporated into the design and
that the emergency shutdown procedures are operational.
6.3.6 The senior person responsible for the apparatus should
attend when the apparatus is started at the beginning of the
authorisation for a period of at least 1 hour to ensure that all is
well and to enable teething problems to be identified and
remedied. Thereafter the responsible person should periodically
check the apparatus, especially at the beginning of each
working day, and instruct the Caretakers or evening staff in the
operation of the emergency procedures before the apparatus is
left overnight.
6.3.7 Apparatus found running without an authorisation should
be reported to a nominated senior member of staff or the
Manager, who should take appropriate steps to isolate the
apparatus safely.
6.3.8 Managers should ensure that adequate training,
instruction and information is given to all personnel who will
have to operate the system of work including those who may be
affected by the operation of unattended apparatus.
Appendix 1
Portable electrical appliance - visual inspection check list
Warning notice
Before any inspections are carried out on appliances, the mains supply MUST be
switched off at the socket outlet and the 13A mains plug removed.
Casing
a) Check the outer casing for any damage or broken parts.
b) Check that there are no exposed electrical connections or parts which can
be touched during normal operating conditions.
c) Check the mechanical operation of the mains switch on the appliance to
ensure correct operation.
Mains supply leads
a) Check that the correct detachable mains lead is connected to the appliance.
b) Check that the outer sheath is firmly anchored to both connection points on
either end of the cable and is free from rotation.
c) Check that the mains cable is correctly protected by sleeting or rubber
grommet where it enters a connector or appliance casing.
d) Check that the cable is free from damage e.g. cuts, burns abrasions, fraying
or signs of overheating.
e) Check that the mains cable is correct for the type of environment e.g. a safe
working length, can be located safely during use or the correct type of cable
used.
Mains plugs and connectors
Exterior Inspection
a) Check that the correct type of 13A mains plug is fitted to the appliance.
(Preferred type MK646 with partly insulated live terminals).
b) Check the plugs and sockets for damage e.g. cracks, breakage’s or signs of
overheating.
c) Check that the tops or lids are firmly attached to the main body of the plug
or connector.
Interior Inspection
a) Check that the cable sheath is firmly secured to the plug or connector.
b) Check that the electrical connections are correctly wired i.e. Brown - LIVE,
Blue - NEUTRAL and Green/Yellow - EARTH. (If any other colour coding is
used, please contact the College Safety Officer).
c) Check that each termination is wired correctly with no exposed electrical
conductors and each terminal is firmly tightened down.
d) Check that the correct fuse is fitted e.g.
Up to 720Watts fit a 3Amp fuse
From 720Watts up to 1200Watts fit a 5Ap fuse
From 1200Watts up to 2400Watts fit a 10Amp fuse
From 2400Watts up to 3000Watts fit a 13Amp fuse.
Note On some occasions it may be necessary to up-grade the mains fuse to
overcome electrical surges when the appliance is switched on e.g. motorised or
inductive equipment. If any problems are encountered, please seek advice from a
competent person.
Appendix 1a
Portable electrical appliance – initial schedule of test & inspection
All electrical equipment covered by this code of practice shall be inspected
before first use and thereafter routinely inspected and tested as detailed in
the table below for at least four test periods. Experience of operating this
system over a period of time, together with fault information, may be used
to review the frequency of future inspection and testing providing no period
exceeds 36 months.
This table is intended as a guide only and the test/inspection frequency can
be reduced or increased by the competent person appointed by the Manager
responsible for that equipment, based upon past experience and their risk
assessments. However, caution should be exercised with Class l hand-held
equipment, which should not have an inspection/test period greater than 12
months.
Key to Groups:Group “A” - Hand held or operated whilst connected to the supply.
Group “B” - All other items connected via 13Amp plug but excluding
Group “C & D”.
Group “C” - Business Equipment.
Group “D” - Low Voltage Equipment e.g. below 50 volts.
Location
of use
Office
Classroom
Workshop
Laboratory
Private #
Outside *
Damp/Wet
Group “A” Equipment
Class l
6m
3m
3m
3m
3m
3m
Note B
Class ll
12 m
6m
3m
3m
3m
6m
3m
Class lll
24 m
12 m
6m
6m
6m
12 m
6m
Group “B” Equipment
Class l
12 m
12 m
6m
6m
3m
3m
Note B
Class ll
24 m
24 m
12 m
12 m
6m
6m
3m
Class lll
Note C
Note C
36 m
36 m
12 m
12 m
6m
Group “C” Equipment
Class l
24 m
12 m
12 m
12 m
See note
See note
See note
Class ll
36 m
24 m
24 m
24 m
A below
B below
B below
Class lll
Note C
Note C
Note C
Note C
Note C
Note C
Note C
Group “D”
Equipment
36 m inspection
36 m inspection
36 m inspection
36 m inspection
See note A below
36 m inspection
36 m inspection
All periods shown in months.
* All mains powered equipment used outside must be supplied via a 30mA 30mS RCD.
# The use of privately owned electrical equipment on College premises must be sanctioned by the
Estates dept annually.
Note A:
Student Owned Equipment - Inspected on first use thereafter
each term.
Staff Owned Equipment – Inspected on first use thereafter
annually.
Note B:
Equipment is likely to be unsuitable for the environment and
special arrangements will be needed.
Note C:
Testing is not normally required for Class lll equipment although
an inspection every 36 months is considered advisable.
Group ”D” equipment is likely to require inspection for damage only unless
having undergone repair on the mains supply
Related documentation
Health and Safety Management Guidelines
College Health, Safety & Welfare Policy
First Issued 21 February 1994
Amended 07 October 1999, 16 October 2002, July 2014