Estates Section
Procedures for work on
fixed electrical installations
CONTENTS
1.0
Introduction
2.0
Hazards and risks associated with work on electrical systems
3.0
3.1
3.2
3.3
3.4
Duties of Estates Section electrical staff
Clerk of Works (Maintenance), Senior Maintenance Electrician and Chargehand
Electrician
Electricians
Assistants
M&E Project Engineers
4.0
Approved tools and equipment for use by Estates Section Electrical Staff
5.0
5.1
5.2
5.3
5.4
5.5
Procedures for carrying out electrical isolations
Procedure for carrying out an electrical isolation (General)
Procedure for the electrical isolation of a motor or pump
Procedure for isolation of main switches on incoming low voltage switchboards
De-isolations.
Neutral conductors on older circuits
6.0
6.1
6.2
Procedure for work on electric cables
Methods of tracing cables
Redundant cabling
7.0
Procedure for earthing low voltage equipment
8.0
8.1
8.2
8.3
8.4
8.5
8.6
Procedures for padlocking and posting of caution notices on isolations
Padlocks used by Estates Section staff
Work on low voltage installations (General)
Work on mechanical equipment
Isolations where multiple padlocks cannot be applied
Isolations where it is not possible to apply a padlock
Procedure for removal of a padlock when the owner is absent
9.0
Switching programmes
10.0
10.1
10.2
10.3
10.4
10.5
Procedure for work carried out adjacent to exposed live conductors
Scope of this procedure
How to decide whether the work will ‘forseeably give rise to danger’
Requirements of the Electricity at Work Regulations 1989
Authorisation for work
Minimum precautions required for all work on or near live conductors which may
foreseeably give rise to danger
10.6 Removal/replacement of covers designed to shroud exposed live conductors
11.0 High Voltage Equipment
12.0 Potentially explosive atmospheres
13.0 Rules for contractors working on University electrical systems
14.0 Projects Isolation Request Form – guidance on completion for an electrical
isolation
Revision 1
Document revised by: Ian Cowe
Approved by:
Gordon Mathieson, Bob Philp, Alan Wight.
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Procedure for Fixed Electrical Installations
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1.0
INTRODUCTION
On average, 20 people are killed in the UK every year by electrical accidents whilst at
work - most of these accidents are preventable.
The Electricity at Work Regulations 1989 requires precautions to be taken against the
risk of death or personal injury from electricity in work activities.
The purpose of these procedures is to put in place a system of control measures to
prevent injury to University Staff and contractors from the hazards and risks associated
with work on electrical systems at the University.
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2.0
HAZARDS AND RISKS ASSOCIATED WITH WORK ON ELECTRICAL SYSTEMS
Electric shock
Electric shock occurs when a person makes contact with a live conductor while
simultaneously in contact with an earthed object or another live conductor at a lower
potential and current passes through the body. The effects of electric shock include:
•
•
•
•
Muscular contractions causing involuntary gripping of the live source and being unable to
let go.
Cardiac arrest.
Electric burns caused by the heating effect of having electric current passing through the
body, these can be deep seated internal burns which take a long time to heal.
Momentary loss of control or balance, this can lead to injuries from falls (e.g. whilst
working from a ladder).
Factors in the surrounding environment that can increase the likelihood of electric shock
include wet or damp conditions or areas where there is a high proportion of earthed
metal in cramped surroundings.
Electric arcing
Electric arcing can occur where the potential in a conductor is great enough to create a
conductive path across an air gap or insulation material to a conductor at a lower
potential. Although arcing may only occur for a short period very large amounts of energy
can be involved.
Arcing generates ultra-violet radiation that can cause severe burns to the skin and the
retina of the eye. Arcing can also cause fire and explosion (see below).
Fire
Fires may be started by electricity in a number of ways including:
•
•
•
•
Overheating of cables and electric equipment due to overloading of conductors.
Leakage of current due to poor or inadequate electrical insulation.
Overheating of flammable materials placed too close to electrical equipment.
Flammable materials being ignited by an electric spark, arc or the spattering of hot
particles from electrical equipment.
Electrical explosions
Electrical explosions can be caused by:
•
•
Electrical equipment subjected to excessive currents or prolonged internal arcing faults.
The energy overload causes the sudden and catastrophic rupturing of the equipment.
Flammable gases or vapours being ignited by an electric spark, arc or the hot surface of
electrical equipment.
Electrical explosions can cause injuries including severe burns from hot metal particles
or molten metal, injuries from flying debris and those caused when the body is thrown
against some obstacle by the blast.
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3.0
DUTIES OF ESTATES SECTION ELECTRICAL STAFF
The following persons are authorised to carry out the tasks listed below:
Maintenance staff
3.1
•
•
•
3.2
•
•
•
•
•
3.3
•
Clerk of Works (Maintenance), Senior Maintenance Electrician, Chargehand
Electrician
Write a Switching Programme.
Supervise work on or near live conductors which may foreseeably give rise to danger.
All of the tasks for electricians and assistants.
Electrician
Work on low voltage lighting, small power equipment and circuits.
Work on dead low voltage equipment.
Carry out testing and fault finding on live/dead equipment.
Work on or near live conductors which may foreseeably give rise to danger under
supervision.
Work in main low voltage switchrooms under supervision.
Assistants
Work on dead low voltage equipment under supervision.
Projects staff
3.4
•
•
•
M&E Project Engineers
Write a Switching Programme.
Carry out an electrical isolation.
Supervise work on or near live conductors which may foreseeably give rise to danger.
Note: for the purpose of these procedures low voltage is classed as any voltage below
650V ac.
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APPROVED TOOLS AND EQUIPMENT FOR USE BY ESTATES SECTION
ELECTRICAL STAFF
Estates Section staff are only permitted to use authorised equipment that has been
issued by the Senior Electrician/Chargehand Electrician.
The use of unauthorised personal equipment is forbidden.
The Senior Maintenance Electrician maintains a list of the personal tools and equipment
issued to all Estates Section electrical staff and a list of the equipment kept at Bedford
Road . The lists are used to ensure that tools and equipment have been checked and
where necessary calibrated.
User checks before using test equipment.
Check the general condition of the test device (including all leads, probes and
connectors) - look for cracked meter cases, damaged insulation or loose terminals.
Check that test equipment has a label indicating that it has been calibrated within the last
12 months.
The equipment must be taken out of use if any defects are found, defects must be
reported to the Senior Maintenance Electrician or Chargehand Electrician.
Use of ladders and stepladders for electrical work
All ladders and stepladders used by Estates Section personnel whilst carrying out
electrical work must be glass fibre type. Use of ladders and stepladders must be in
accordance with the procedure for safe use of ladders and stepladders.
•
•
•
The following inspection regimes will apply to all equipment.
Users to check each time before use (see above).
Quarterly inspections of all tools and equipment by Senior Maintenance
Electrician/Chargehand Electrician.
Equipment used for testing or measuring (including personal issue multimeters) to be
calibrated annually by an accredited calibration organisation
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5.0
PROCEDURES FOR CARRYING OUT ELECTRICAL ISOLATIONS
Prior to carrying out isolations, checks must be carried out to ensure that the sudden loss
of power to items being served by the power supply will not compromise safety or cause
disruption. Examples of equipment where the sudden loss of power could compromise
safety or cause disruption include fume cupboards, microbiological safety cabinets,
workshop machinery, pumps and freezers.
5.1
Procedure for carrying out an electrical isolation (General)
Note: The Senior Electrician/Chargehand Electrician must be contacted prior to
any work being carried if the distribution board or consumer unit is found to be
unsafe to work on (e.g. Covers missing leaving live parts exposed).
1) Identify the circuit to be isolated
(Refer to circuit charts or use a fuse finder if charts are poor or do not exist).
2) To isolate the circuit carry out one of the following:
a) Switch off circuit breaker or isolator and lock off.
OR
b) Remove the fuse and carrier. Apply locking device to the fuse carriage and lock off.
Note: Fuses that have been removed must be retained by the person responsible for
the isolation and not left lying on distribution board shelves or rooms.
If neither of the above is possible contact the Senior Electrician/Chargehand
Electrician (Maintenance) prior to carrying out any work.
3) Post caution tags on the circuit breaker OR on the lock in the fuse carrier.
Note: Taping over fuse carriages or posting caution tags on the distribution board door is
NOT acceptable.
The caution tag must state the person carrying out the isolation and the reason for the
isolation.
4) Part 4 continued on next page.
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Procedure for Fixed Electrical Installations
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4) To test the circuit to prove that it is dead the following must be done:
Note: Authorised equipment MUST be used (see section 4.0).
(i)
If using a multimeter ensure that the correct function (voltage testing) has been
selected.
Note: All multi-meters issued to staff will be a type that will not give rise to
danger if inadvertently put to an incorrect setting.
(ii) Prove the test meter by applying the leads to the test unit.
(iii)
•
•
•
•
Apply the testing leads to the electrical equipment to be worked on in this order.
Each phase & earth
Each phase & neutral
Each phase to phase
Neutral to earth (if the neutral has been disconnected)
(iv) Prove the test meter again by applying the leads to the test unit.
Note: In the case of testing that a socket has been isolated a Martindale plug in tester
may be used. The plug in tester must be proved on a live socket before and after the
check on the socket that is being proved dead.
5.2
Procedure for the electrical isolation of a motor or pump
1) Switch off the isolator serving the motor.
2) If it cannot be confirmed that the isolator is a 2 pole isolator (for single phase) or 4-pole
type isolator (for 3 phase), then open the isolator cover to check that the neutral link has
been physically separated. If the neutral link has not been physically separated, drop the
neutral link (this is assuming the isolator has a neutral which can be dropped).
Note: should any covers be broken or missing exposing live parts the Senior
Electrician/Chargehand Electrician (Maintenance) MUST be contacted before the works
proceed.
3) Lock off and post caution tag.
4) Remove cover of the motor and prove that power supply to the motor is dead.
De-isolation of motor
Re-connect the neutral link prior to the de-isolation being carried out.
After carrying out a de-isolation check that the motor is operating in the right direction by
momentary switching the motor on.
Note: The above test should be satisfactory for most applications. In rare cases where
phase rotation tests are required (i.e. tests which are carried out with covers removed
and there are exposed live parts where there is a foreseeable risk of danger) then the
procedures listed in section 10.0 will apply.
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5.3
Procedure for the isolation of main switches on incoming low voltage
switchboards
In addition to the isolation and locking off of the main switch the following must be carried
out:
1) Uninterrupted Power Supply (UPS) to be shut down and isolated:
• Procedure for shutting down the UPS system listed in the operating manual to be
followed.
• Switch off and isolate the power supply from the UPS. Lock off and post caution tag.
• Switch off and isolate the power supply to the UPS on the main LV board. Lock off
and post caution tag.
2) Standby generator to be isolated and locked off:
• Push stop buttons (external and internal)
• Turn selector switch from ‘auto’ to ‘stop’/off
• Switch main circuit breaker to off position
• Disconnect battery tails
• Senior Maintenance Electrician/Chargehand Electrician to apply personal padlock
and caution tag.
• Senior Maintenance Electrician/Chargehand Electrician to remove key and place in
lockout box.
5.4
De-isolations
Tests required prior to the system being de-isolated
Systems or equipment which have been worked on must not be de-isolated until copies
of the tests required by BS7671: 2008 (the IEE Wiring Regulations 17th Edition) have
been supplied to the person carrying out the de-isolation.
Re-connection of the neutral conductor
In cases where the neutral conductor has been disconnected (e.g. in an older type
isolator), the neutral conductor must be re-connected prior to the de-isolation being
carried out.
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5.5
Neutral conductors on older circuits
The subject of work on older circuits and the risk from neutral conductors is a complex
one. On newer circuits this should not be a problem, however on older circuits there is a
risk that the dangerous practice of borrowing neutrals may have been carried out (i.e. the
neutral in one circuit is used in another circuit and is not from the same distribution
board/source as the live conductor). The risk is that a borrowed neutral which has been
used in another circuit could be live when disconnected (or become live if the other
circuit is switched off at the time of disconnection but subsequently re-energised) –
anyone coming into contact with the neutral could be electrocuted.
There are arguments for and against disconnecting neutral conductors if carrying out
work on older circuits. The arguments for disconnection are that by disconnecting the
neutral conductor the circuit to be worked will then be isolated from any source of
potential power.
The arguments against disconnecting the neutral are that a neutral which has been
borrowed can become live once it is disconnected and there is a risk of electrocution
should someone come into contact with it. There can also be a risk of fire if a neutral
conductor which has been disconnected on a 3 phase board is not reconnected when
that board is reenergised.
For this reason work involving older boards will need to be considered on a case by case
basis, however the following guidelines will apply:
•
Staff should be aware that on older circuits borrowed neutrals could be an issue.
•
Neutrals should be treated as being potentially "live". Tests should be carried out
between neutral and earth for any voltage if the neutral is disconnected. Note: the
test will only work if the other circuit is energised at the time the neutral is
disconnected.
•
ALL neutrals which have been disconnected should be terminated into separate
terminal blocks. They should be treated as being potentially ‘live’ when being
reconnected.
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6.0
PROCEDURE FOR WORK ON ELECTRIC CABLES
Electric cables must not be worked on unless they have been proved dead and
can be traced from the point of work all the way back to a SECURE ISOLATION at
the switchboard.
6.1
•
Methods of tracing cables
The following methods of tracing cables are acceptable:
Visually tracing the cable all the way back to the switchboard.
Note: Pulling at cables is not an acceptable method of tracing cables as other cables can
be wrapped around the cable.
•
In cases where the cable terminates at a socket - using a fuse finder to locate the fuse or
circuit breaker for the cable.
•
In cases where the cable is found to be live and does not terminate at a socket outlet using a non-contact voltage detector on the cable and an Estates electrician switching off
circuit breakers/pulling fuses until the circuit breaker/fuse for the cable has been located.
Notes:
i)
The voltage tester being used must be suitable for the type of cable being tested
(refer to manufacturers instructions for suitability).
The non-contact voltage detector must be proved against a known live source
before and after testing the cable. The cable must be separated from other cables
when the tests are carried out.
ii)
Using the non-contact voltage alone without actually going and tracing the cable
back to its source is not acceptable as the final means of proving whether a cable
is live or dead.
The cable must be labelled stating who proved it dead, when it was proved dead
and the circuit breaker/fuse for that cable.
6.2
Redundant cabling
Cabling that is no longer required must be stripped out back to the switchboard.
Exceptional cases where this is not possible must be referred back to the Estates
Section person commissioning the works. Should the person commissioning the works
decide that it is unreasonable to remove the cable, the cable must be physically
disconnected at both ends, tied up and labelled.
Under no circumstances should cabling be left connected to a power source once
it has been disconnected from the equipment it originally supplied.
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7.0
PROCEDURE FOR EARTHING LOW VOLTAGE EQUIPMENT
Additional local earths may be required if:
•
The point of work is remote from the point of isolation.
•
There is a chance that the equipment or circuits may retain an electrical charge (due to
capacitance or induction) after disconnection from the power source. Examples include
switchboards fed from transformers on a high voltage system and large motors.
Should electrical staff be in any doubt whether additional local earths may be required
they should contact the Senior Maintenance Electrician/Chargehand Electrician.
The following PPE must be worn when connecting and disconnecting leads:
•
•
Rubber gauntlets (rated 1000V) – to BS EN 60903:1993
Note: Ensure that the replacement date stamped on the gauntlet has not expired.
Visor
The following sequence of operations must be carried out when connecting and
disconnecting leads:
•
•
•
•
•
Carry out checks to ensure that the equipment or circuit is dead and has been securely
isolated (see section 5.1).
Check portable leads for any defects, check that leads have are suitably rated to deal
with any short circuit currents.
Connect leads to earth before connecting to each phase conductors, then link up each of
the phase conductors.
Check that good contact has been made. Leads must be labelled to identify them as an
additional earth.
When removing portable leads, disconnect leads from phase conductors first and then
from earth.
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Procedure for Fixed Electrical Installations
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8.0
PROCEDURES FOR PADLOCKING AND POSTING OF CAUTION NOTICES ON
ISOLATIONS
8.1
Padlocks used by Estates Section staff
Estates Section staff are only permitted to use padlocks that have been issued by the
Senior Maintenance Electrician/Chargehand Electrician.
All padlocks used by Estates Section staff will have unique keys with no duplicate keys
being held.
8.2
•
Work on low voltage installations (general)
The padlocks of all persons (including contractors) working on the low voltage installation
must be applied at each point of isolation. The Estates electrician carrying out the
isolation must apply a caution notice at each point of isolation.
•
The padlock of the Estates electrician carrying out the isolation must be the first padlock
applied to the isolation and the last padlock removed prior to de-isolation.
8.3
•
Work on mechanical equipment
Where isolations are required to enable work to be carried out on an item of mechanical
equipment (e.g. pump), the padlocks of all engineers working on the job must also be
applied at each point of isolation.
8.4
•
Isolations where multiple padlocks cannot be applied
On some small lighting and power circuits it may not be possible to apply multiple
padlocks at the point of isolation.
•
In this case the padlock of the Estates Electrician will be applied, the key for the padlock
must then be put in the lockout box and the padlocks of all those involved in the works
(including contractors) applied to the lockout box. The lockout box must then be taken to
nearest electrical workshop.
•
The Estates Section electrician must apply a caution notice at the point of isolation.
8.5
•
Isolations where it is not possible to apply a padlock
Where it is not possible to apply a padlock (e.g. older type switchboards with fuse
carriers which cannot be locked off), the Senior Electrician or Chargehand Electrician
must be contacted.
•
The phase cable to the fuse carriage must be disconnected, the end taped and a caution
tag applied to the end of the cable - taping over fuse carriage holders and leaving the
circuit cables connected is NOT acceptable.
Note: this work must be done with the switchboard dead and securely isolated.
•
The fuse carrier should then be put back into the board without the fuse, this will ensure
that the live parts of the board are covered.
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8.6
Removal of padlocks in the absence of the owner
The removal of padlocks will only be permitted in exceptional circumstances (i.e. the
consequences for the University of not removing the padlock are operationally or
financially unacceptable).The removal of a padlock MUST be authorised by an Assistant
Estates Director.
The sequence below must be followed before approval is given. This page should be
printed off, completed and retained by the Assistant Estates Director.
1) What is the reason for the urgent removal of the padlock and why can it not wait until
the owner is available?
2) Has the owner of the padlock been contacted and notified that their padlock has
been removed, if so, have they given their approval for their padlock to be removed?
3) If the owner of the padlock cannot be contacted, has their line manager/supervisor
been contacted, if so, have they given their approval for the padlock to be removed?
Note: in both cases 2 and 3, a reply must have been received from the person (i.e.
leaving messages on answerphones, sending texts or e-mails but not receiving a
reply back from the person is not acceptable).
4) What precautions are to be taken to prevent danger to staff removing the padlocks,
entering the area and re-energising services?
5) If the padlock has been removed from an item of equipment, have notices been
posted on the item of equipment from which the padlock has been removed?
6) If the padlock has been removed from an area, have notices been posted on ALL
entrance points to the area?
Note: signage posted must state the following “Work on this item of equipment/entry
to this area is prohibited, contact (insert name and contact details of the AED who
approved the removal) for further details”.
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Procedure for Fixed Electrical Installations
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9.0
SWITCHING PROGRAMMES
Switching programmes will be written for systems being worked on where there is more
than one source of supply (e.g. generators, uninterrupted power supplies and parallel
feeds) and there is a risk of a switching error being made.
The Switching Programme must be:
•
Written by one of the persons authorised to write a Switching Programme and checked
by another person authorised to write a switching programme (refer to section 3.0)
•
Clearly detail the exact sequence of operations for the isolation and de-isolation.
•
Explained on site to the person who will carry out the switching operation. The person
who will carry out the switching operation must clearly demonstrate that they have
understood the switching sequence and the reasons for it.
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10.0 PROCEDURE FOR WORK CARRIED OUT ON OR NEAR LIVE CONDUCTORS
WHICH MAY FORESEEABLY GIVE RISE TO DANGER
10.1 Scope of this procedure
This procedure covers work on or near live electrical conductors which may foreseeably
give rise to danger. Work includes electrical testing and work activities that are not
electrical in nature but are carried out near live electrical conductors.
Work on or near live conductors which may foreseeably give rise to danger will rarely be
permitted by the Estates Section.
10.2 How to decide whether the work will ‘forseeably give rise to danger’
When carrying out any work on or near live conductors the electrician who will carry out
the work must carry out an initial risk assessment of the work based on the following
factors:
•
The amount of exposed live conductors (e.g. metalwork).
•
The possibility of electric shock from physical contact with the exposed live conductor,
arcing whilst being in proximity to the exposed live conductor, or dropping something
onto the live conductor.
•
The location where the work is to be carried out (i.e. can the area be easily secured or
is it in a busy place).
10.3 Requirements of the Electricity at Work Regulations 1989
The Electricity at Work Regulations 1989 states that work on or near live conductors
which may foreseeably give rise to danger will only be permitted if the following three
conditions are satisfied:
(i)
(ii)
(iii)
It is unreasonable in all circumstances for the live conductor to be made dead.
It is reasonable in all circumstances for the person to be at work on or near the live
conductor.
Suitable precautions (including where necessary, the provision of personal
protective equipment) are taken to prevent injury.
10.4 Authorisation for work
In view of the strict requirements laid out in the Electricity at Work Regulations and the
potential risks, cases where the risk assessment highlights a foreseeable risk of danger
from the live conductor must be referred to the Assistant Estates Director with
responsibility for the work prior to the work being carried out.
The Assistant Estates Director will decide if the work can proceed based on the three
conditions necessary for work on or near live conductors which may foreseeably give
rise to danger listed in the Electricity at Work Regulations 1989.
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10.5 Minimum precautions required for all work on or near live conductors which may
foreseaably give rise to danger
Risk assessment and method statement
The authorised person (see section 3.0) supervising the work must carry out a written
risk assessment for the work. A method statement must then be written detailing exactly
how the work will be carried out and the safety precautions to be taken.
•
•
•
•
Personal protective equipment
Required
Insulated tools – to BS EN 60900: 1994
Optional (depending on results of risk assessment and the precautions required)
Rubber gauntlets (rated 1000V) – to BS EN 60903:1993
Note: Ensure that the replacement date stamped on the gauntlet has not expired.
Visor
Arc proof boilersuit
In addition to the above PPE loose metal jewellery should be removed. Metal objects
kept in pockets such as coins, keys, lighters etc must be removed to prevent anything
falling out onto live parts during the work.
•
Area where work is to be carried out
The work area must be checked to ensure that:
(i)
There is adequate working space.
The HSE publication HSG85 Electricity at Work Safe Working Practices states that
where there are exposed live parts at 400V or above, the clear working space
should not be less than 1m. Where there are live parts exposed on each side of the
working space the clear working space should not be less than 1.4m.
(ii) Floors are free from any slip and trip hazards.
(iii) Lighting levels are adequate.
•
In some areas effective barriers may be required to keep unauthorised persons away
from the work area.
•
Warning notices must be posted at the entrance to the area to prevent unauthorised
entry.
•
Protective screening may be required to screen live parts. Any protective screening used
must be suitable for that purpose.
Accompaniment of person carrying out the work
The person carrying out the works must be accompanied at all times by another Estates
Section electrician with the competence to keep unauthorised persons away from the
area, recognise danger, switch off power in the event of an emergency, radio for
assistance and provide first-aid to the injured person.
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10.6 Removal/replacement of covers designed to shroud exposed live conductors
Covers which shroud live conductors should not be unscrewed or unbolted whilst the
equipment is still live. The reason for this is that what is behind the cover is unknown and
any loose parts (e.g. screws, cables etc) or the cover itself could come into contact with
the live conductor. The same would apply to replacing covers which shroud live parts.
Examples include:
•
Screwed or bolted covers on distribution boards and consumer units.
•
Covers on power sockets and light switches.
Covers which shroud live conductors may sometimes have to be removed in order to
carry out live fault finding on equipment. The equipment should be isolated and locked
off before unscrewing or unbolting the cover. The equipment should also be isolated and
locked off before screwing or bolting the cover back into place.
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11.0 HIGH VOLTAGE EQUIPMENT
The University owns a number of high voltage installations - a specialist contractor
maintains these.
•
Estates Section electrical staff are not permitted to work on any high voltage equipment.
•
Estates Section electrical staff must not enter any HV substations unless authorised and
accompanied by the Clerk of Works (Maintenance), Senior Maintenance Electrician,
Chargehand Electrician or M&E Project Engineers.
Note: for the purposes of these procedures high voltage is classed as any voltage above
650V ac.
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12.0 POTENTIALLY EXPLOSIVE ATMOSPHERES
There are several areas around the University where there is the potential for an
explosive atmosphere to develop due to the nature of the items being stored (e.g.
solvent or chemical stores). Flameproof/intrinsically safe fittings have been installed in
these areas.
University Maintenance staff are not permitted to work on the
flameproof/intrinsically safe fittings in these areas.
All works in these areas to be carried out by a specialist contractor with the permission of
the Technical Resources Officer responsible for the area.
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13.0 RULES FOR CONTRACTORS WORKING ON UNIVERSITY ELECTRICAL SYSTEMS
Note: it is the responsibility of the Estates Section representative (Maintenance or
Projects) commissioning the works to explain these rules to the electrical
contractor prior to the works being carried out.
13.1 Isolations/de-isolations
•
Contractors MUST NOT carry out any isolations or de-isolations on University
switchgear.
•
Isolations must be carried out by Estates Section electrical staff in the presence of the
electrical contractor’s competent representative.
•
The contractor is responsible for checking the safe and secure isolation of all
electrical equipment or circuits to be worked on or which the works could disturb.
Contractors must carry out their own tests to confirm that equipment or circuits they will
work on or could disturb are dead.
The contractor’s padlock must be applied to all equipment or circuits that they are going
to work on. In cases where this is not possible (i.e. only one padlock can be applied)
then a lock-out box will be used. UoA electricians will apply their padlock to the circuit,
the key will then be put into a lock-out box. The contractor will then apply their padlock to
the lock-out box along with a second padlock applied by the UoA electricians.
•
Testing equipment used by contractors must be marked to indicate that it has been
calibrated within the last 12 months.
•
Prior to de-isolations being carried out, contractors MUST forward copies of the dead
tests required by BS7671: 2008 (IEE Wiring Regulations 17th Edition) for the work they
have carried out to Estates Section.
13.2 Scope of works
•
Contractors MUST NOT deviate from the scope of works agreed with the Estates
Section representative commissioning the works.
13.3 Redundant cabling
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Only electricians may cut electrical cables.
•
Electrical cables may only be cut if they can be traced back to their source, the source
must be securely isolated.
•
Cables which are cut must be stripped out, if this is not possible then the Estates Section
representative commissioning the works must be informed.
•
Refer to Section 6.0 of these procedures for details on the checks to be carried out when
tracing cables.
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Procedure for Fixed Electrical Installations
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14.0 PROJECTS ISOLATION REQUEST FORM - GUIDANCE ON COMPLETION FOR AN
ELECTRICAL ISOLATION
•
The only Projects staff who are authorised to complete a request for an electrical
isolation are the M&E Project Engineers. If any other staff (e.g. Building Clerks of
Works) require an electrical isolation it must be referred to one of the M&E Project
Engineers.*
•
Maintenance staff will normally isolate electrical services on behalf of Projects. On some
occasions it may be more efficient for one of the M&E Project Engineers to carry out the
isolation themselves. In this case a Projects Isolation Request Form will still need to be
completed by this person.
•
An individual form is required for each area to be electrically isolated (i.e. electrical
isolations for two completely separate areas require two separate forms). Requests for
isolation of other services (e.g. fire alarm, water etc) must not be put on the same form.
•
Forms must not be faxed.
14.1 SECTION 1 OF FORM
•
•
•
Parts 1-6
The M&E Project Engineer requesting the electrical isolation, or carrying out the
isolation, must complete parts 1 to 6 of the form. The information in parts 1 to 6 must
contain sufficient detail for the isolation to be carried out (location, circuit board number,
circuit number etc).
Maintenance staff carrying out isolations must only isolate the electrical services listed
on the form. If additional services require isolation a new form must be completed.
Part 7
The isolation may not proceed until:
- The Clerk of Works (Maintenance) has checked Parts 1-6 of the form and signed Part 7
of the white and yellow copy of the form. Note: If the Clerk of Works (Maintenance) is
unavailable then the Senior Electrical Engineer, Chargehand Electrician or Assistant
Estates Director (Maintenance) should carry out the checks and sign this part of the
form.
- The Building Clerk of Works responsible for the area has signed part 7 of the form.
14.2 SECTION 2 OF FORM
•
•
Part 1
This must be completed by the Senior Electrical Engineer or Chargehand Electrician.
confirming that the electrical isolation may proceed. Permission for the isolation should
not be granted if the information in Parts 1 to 7 of the form are either incomplete or do
not contain sufficient information.
Part 3
Part 3 must be completed by the electrical contractor who will actually be carrying out
the work. The isolation must only be carried out if there is an electrical contractor
there to accept it.
* In rare cases the electrical work required may not be part of a project, in these cases the works must be
referred to, and co-ordinated by, the Senior Electrical Engineer/Chargehand Electrician at Bedford Road.
Estates Section
Procedure for Fixed Electrical Installations
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14.3 SECTION 3 OF THE FORM
Part 1
•
Electrical de-isolations MUST NOT be carried out until copies of the dead tests for the
work required by BS7671: 2008 (IEE Wiring Regulations 17th Edition) have been
forwarded to the person who will carry out the de-isolation.
14.4 FILING OF PROJECTS ISOLATION REQUEST FORMS
The Projects representative must collect each of the copies of the form and file these
together in file H PRO ISO kept in the Estates office.
Estates Section
Procedure for Fixed Electrical Installations
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