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Directorate of Estates and Facilities Management
Safety Code of Practice
HIGH VOLTAGE SYSTEMS
August 2011
Executive Summary
Plymouth University has a responsibility by law to comply with the Electricity
at Works Regulations 1989. The regulations require in Regulation 4 (2) that
„As may be necessary to prevent danger, all systems shall be maintained so
as to prevent, so far as reasonably practicable, such danger‟.
High Voltage systems operate at voltages exceeding 1KV and for the purpose
of this Code of Practice refer to the Universities 11KV distribution system.
The Code of Practice gives guidance on the safe operation and maintenance
of high voltage systems up to and including 11KV and it is applicable up to
and including the first point on the low voltage system.
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1 Introduction
The University has two high voltage networks incorporating 11 substations
increasing to 12 when the new Marine building is complete. The two high voltage
distribution networks have a Western Power Distribution (WPD) 11KV exit point at
the main intake (the boundary) and are operated as radial circuits with a normally
open point.
High voltage systems are defined as those that operate at voltages exceeding 1000V
ac or 1500V dc between conductors and/or 600volts ac or 900volts dc between
conductors and earth.
This Code of Practice applies to the 11KV electrical distribution systems and
equipment. Voltages less than these are considered to be low voltage and as such
fall under the Plymouth University - Safety Code of Practice for Low Voltage
Systems.
This Code of Practice has been devised for the protection and safety of University
employees and other persons who may have cause to work on or near the
University's High Voltage Distribution Networks.
This Code of Practice will be reviewed on a regular basis to incorporate the latest
safety legislation as required.
It is the responsibility of all persons who may be concerned with the control,
operation, working or testing, on or in the near vicinity of electrical equipment to
which this Code of Practice applies, to implement and to comply with them and with
related Codes and Procedures.
The operation and servicing of high voltage equipment in accordance with clearly
defined rules and procedures should be entrusted only to persons who are appointed
by an Authorising Engineer, these will be appointed in writing as „Authorised
Persons‟.
Wherever possible, the system of work is to match that as laid out in HTM 2021
documentation, which is kept in the dedicated „Authorised Person Office‟ in 18
Endsleigh Place, Plymouth.
To satisfy the requirements of the Electricity at Work Regulations 1989 and HTM
2021 the University must have:
a clearly defined safety policy for the operation of and the servicing of the
High Voltage distribution network and equipment, High Voltage Code of
Practice.
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means by which the policy and programme can be managed, implemented,
monitored and reviewed. – Authorised Persons and University Safety
Committee.
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2 References
The references below are statutory requirements and related documentation, this list
is not exhaustive.
Electricity at Work Regulations 1989
Electricity Safety, Quality and Continuity Regulations 2002
Electrical Equipment (Safety) Regulations 1994
Health and Safety at Work Act 1974
HSG47 – Avoiding Dangers from Underground Services
HTM 2021 – Electrical Safety Code for High Voltage Systems
BS6626 – Maintenance of Electrical Switchgear and Control gear for Voltages
above 1KV and up to and including 36KV – Code of Practice
BS EN50110 - Operation of electrical installations
Control of Asbestos Regulations 2006
Fluorinated Greenhouse Gases Regulations 2009
RoHS Regulations 2008
HSR 25 Memorandum of Guidance on the Electricity at Work Regulations
1989
MSA 19 PCB‟s and you. Do you know how to work safely with PCB‟s? – HSE
publication.
HSG230 – Keeping Electrical Switchgear Safe
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3 Definitions
The following definitions apply through this Code of Practice.
Authorising Engineer (High Voltage) – a chartered electrical engineer with
appropriate experience, possessing the necessary degree of independence from
local management, who is appointed to implement, administer and monitor the safety
arrangements for the high voltage electrical supply and distribution systems of that
organisation to ensure compliance with the Electricity at Work Regulations 1989 and
to assess the suitability and appointment of candidates in writing to be „Authorised
Persons‟.
Designated Engineer – An Authorised person who has overall authority and
responsibility for the high voltage systems. This person should not be the authorising
engineer.
Authorised Person (AP) - an individual possessing adequate technical knowledge,
and having received appropriate training, appointed in writing by the Authorising
Engineer to be responsible for the practical implementation and operation of the high
voltage systems on the premises.
Competent Person – a person recognised by the Authorised Person as having
sufficient technical knowledge and experience to enable them to avoid danger and
who maybe nominated to receive and clear specified safety documents.
Conductor – a conductor of electrical energy.
Danger – a risk of injury.
Dead – neither „live‟ nor „charged‟.
Duty Holder – a person on whom the Electricity at Work Regulations 1989 impose a
duty in connection with safety (Vice Chancellor – University of Plymouth)
Earthing
Earth – the conductive mass of earth, whose electric potential at any point is
conventionally zero.
Earthed - connected to the general mass of earth in such a manner as will
ensure at all times an immediate discharge of electrical energy without
danger.
Circuit Main Earth (CME) – a safety earthing connection of an approved type
applied by an Authorised Person and its position recorded before the issue of
a safety document.
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Additional Earth - earthing equipment of approved type which is applied after
the issue of a Safety Document (for example an earth applied at a point of
work).
Electrical Equipment – includes anything used, intended to be used or installed for
the use to generate, provide, transmit, transform, conduct, distribute, control,
measure or use electrical energy.
High Voltage (HV) – Voltages exceeding 1000Vac or 1500Vdc.
Isolated – the disconnection and separation of electrical equipment and circuit
conductors, by use of an isolating device from every source of electrical energy in
such a way that its disconnection and separation is secure.
Isolating Device – a purpose designed item of equipment which provides a secure
method of disconnecting and separating electrical equipment and/or circuit
conductors from every source of electrical energy.
Key Locker – an enclosure, for all keys associated with the high voltage system.
Key Safe – a small box for the secure retention of keys associated with the safety of
the high voltage system where more than one authorised person is involved.
Low Voltage (LV) – Exceeding extra low voltage but not exceeding 1000V ac or
1500V dc between conductors or 600V ac or 900V dc between conductors and
earth.
Logbook – a pro-forma logbook in which should be recorded:
All switching operations and precautionary measures taken
The issue/clearance/cancellation of all safety documentation
Safety programme serial number
any dangerous occurrences
Live - electrically charged.
Mimic diagram – a permanently displayed single line circuit diagram that shows the
complete high voltage system and any associated low voltage back-feeds.
NOP – Normally Open Point
Notices –
Caution Notice (CN) - a notice conveying a warning against interference.
Danger Notice (DN) - a notice conveying a warning of live equipment.
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Safety Documents - the documents issued by the University Authorised Person to
be one of the following:
Limitation of Access (LOA) – a safety document which is issued and
cancelled by an Authorised Person. It defines the limits and nature of non-
electrical HV work which may be carried out in the vicinity of live electrical
equipment.
Permit to Work (PTW) – a safety document which is a form of declaration
signed and issued by the Authorised Person, to a person in charge of work to
be carried out on any high voltage equipment. It makes known to such a
person exactly what equipment is dead, isolated from all live circuit
conductors, has been discharged, is connected to earth and is safe to work
on.
Sanction for Test (SFT) – a safety document which is a form of declaration
signed and given by an Authorised Person to a person in charge of testing
high voltage electrical equipment. It makes known to such person exactly
what equipment is to be tested and the condition under which testing is to be
carried out.
Safety Lock - a unique lock normally red in colour used for locking off the points at
which a circuit can be energised and is different from all other standard locks used
on the system.
Switching - the operation of circuit breakers, switchgear or other methods of making
(closing) or breaking (opening) an electrical circuit conductor(s) and/or the
application and removal of Circuit Main Earths (CME's).
Switching Schedule - a document prepared by the Authorised Person, and
approved by the other Authorised Person/Authorising Engineer which defines the
work to be done, the sequence of operations, the earthing required and any
alternative supply arrangements.
Switching Device (switchgear) – equipment which has been designed and
manufactured specifically for the purposes of switching electrical energy.
Sub-Station – any premises, or part of premise in which electrical energy is
transformed or converted to or from high voltage, or contains high voltage
switchgear.
Supervision
Immediate – attends the work site at all times but not necessarily in the
presence of the person being supervised.
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Personal – at all times in the presence of the person being supervised so that
if appropriate they can physically restrain them.
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4 Role and Responsibilities
Plymouth University will appoint one Authorising Engineer and two Authorised
Persons (one of which is to act as the Designated Person) to maintain, monitor and
operate their high voltage distribution systems as detailed.
4.1 Role of the Authorising Engineer
The University Authorising Engineer will be responsible for implementing,
administering and monitoring the high voltage system and operation in accordance
with legislation and guidance documentation. The Authorising Engineer roles include
the following:
Appoint in writing sufficient „Authorised Persons‟ to provide the necessary
cover for all the systems and installations for which the University has
responsibility.
Define the exact extent of the system and installations for which each
Authorised Person is responsible.
If necessary suspend or cancel the appointment of an Authorised Person and
withdraw the certificate.
Maintain a register of all Authorised Persons
Ensure that those appointed as Authorised Persons:
- Satisfy the qualifications required by HTM 2021.
- Satisfy the training requirements of HTM 2021.
- Can demonstrate adequate knowledge of each system, installation and
type of equipment for which authorisation is sought.
- Have satisfied the Authorising Engineer as to their competence and ability.
The Authorising Engineer also issues to each Authorised Person, on appointment a
certificate valid for a period not exceeding three years.
Additionally they must review each Authorised Person‟s operational experience at
intervals of not more than three years by examining the relevant operating records of
the system and recommend training as necessary.
4.2 Duties of the Authorising Engineers
On receipt of an „operational restriction‟ related to high voltage systems and/or
equipment, ensure that all Authorised Persons are made aware of it and receive
copies.
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To initiate and co-ordinate, the investigations of reported injuries and dangerous
occurrences involving electrical systems within the Authorising Engineers
responsibility.
4.3 Role of the Designated Engineer
The Designated Engineer will have the same role and responsibilities as that of the
Authorised person (see 4.4 – 4.7) but will have overall ownership and responsibility
for the Universities HV distribution systems. The Designated engineer will not be the
Authorising engineer.
4.4 Role of the Authorised Person
The Authorised person will be responsible for practical implementation of the
requirements contained within the Universities electrical safety policy for the high
voltage systems and installations for which the University has responsibility and for
which the Authorised person has been specifically appointed.
The Authorised persons instruction and decisions on electrical matters for the role
are final. In case of any objections on safety grounds to an Authorised person
instruction, the Authorised person must stop any work or testing to which the
objection is related and refer the matter to the Authorising engineer.
For high voltage distribution networks of a large scale or a complex installation more
than one Authorised person should be appointed. At any one time only one
Authorised person shall have control of the network. The name of the Authorised
person who has control of the network, together with all other details shall be
recorded in the log book and the appropriate notices displayed on the mimic
diagram. Any transfer of responsibility between Authorised persons must also be
recorded in the log book.
4.5 Duties of the Authorised Person
The duties of the Authorised person may be summarised as follows:
Control the work on the high voltage network, prepare inspection,
maintenance and safety programmes and progress work
Ensure that all records concerning high voltage systems are kept up to date
Ensure that test equipment is maintained in good condition and calibrated
when required
Co-operate with the Authorising engineer in matters of policy concerning high
voltage systems
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Report in writing any dangerous occurrences/unusual occurrences to the
Authorising engineer
Appoint in writing Competent persons and maintain a register of all
appointments
Define the duties of appointed Competent persons
Ensure that the necessary safety posters are displayed in Sub-Stations at all
times
Issuing and cancellation of safety documents
High voltage switching operations
Routine inspection and testing of Sub-Station earthing
Routine inspection and testing of transformers and switchgear
Routine inspection and testing of all high voltage protection systems including
batteries
4.6 Qualifications and Training of the Authorised Person
The qualifications required to be eligible for appointment as an Authorised Person
and training programme are detailed in HTM2021.
4.7 Appointment of Authorised Persons
The Authorised Person shall be formally appointed by the Authorising Engineer for
the defined systems and installation. Appointment will be the issue and acceptance
of a certificate signed by the Duty Holder.
4.7.1 Suspension or cancellation of appointment of an Authorised
Person
The appointment of an Authorised person may be suspended or cancel by the
Authorising engineer who should inform them in writing giving the reason for
the suspension or cancellation.
4.8 Competent Person
A Competent Person will be responsible for undertaking duties on high voltage
systems. The limits of these duties will be clearly defined in accordance with the
Authorised Person instructions. While carrying out these duties the Competent
Person must ensure that all safety measures are taken to prevent danger, avoid
injury and prevent damage to equipment.
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4.9 Qualifications for Appointment of Competent Persons
To be eligible for appointment, Competent Person‟s must be:
Be competent to undertake work on the types of system and equipment for
which the appointment is sought
Be familiar with the type of systems and equipment on which work is required
to be undertaken
possess technical knowledge and/or sufficient experience to prevent danger
that may be present by the work to be undertaken
Must have adequate knowledge of:
the relevant parts of the „Electrical Safety Code of Practice for high voltage
systems
any University local rules (see Site Rules and Conditions)
have adequate knowledge of, and within the preceding three years have
received training in, first aid treatment for electric shock.
4.10 Appointment of Competent Persons
A Competent Person should be formally appointed in writing by an Authorised
Person for the duties which are to be clearly defined on the „Certificate of
Appointment‟.
Copies of all Competent Person‟s Certificates are to be placed in the High Voltage
System Operational Procedure Manual located in the dedicated Authorised Person
Office.
Each Competent Persons appointment shall be reviewed by the Authorised Person
at intervals not exceeding three years.
4.10.1 Suspension or cancellation of appointment of a Competent
Person
The appointment of the Competent Person maybe suspended or cancelled an
Authorised Person or the Authorising Engineer.
4.11 Contractors Competent Person
Where a Contractor has been appointed to provide Competent persons for a system
and installation it will be the Authorised persons responsibility to ensure that each
Competent person is of a standard equivalent to that required by this Code of
Practice.
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If the Authorised Person is of the opinion that a Contractors Competent Person is not
working in accordance with the requirements of the „Safety Code of Practice for high
voltage systems‟ or is working in an unsafe manner, the Authorised Person has the
authority to stop the work.
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5 Safe Working Practices
5.1 Safety Procedures
It is a requirement of the Electricity at Work Regulations 1989 that properly
formulated and regulated safety procedures are instituted as a prerequisite to a safe
system of working.
It is therefore essential that all work on high voltage systems, including equipment
and cables, or work which can be dangerous because of its close proximity to high
voltage systems is formalised in written instructions and/or electrical safety rule.
The writing of instructions help those involved to decide the manner in which the
work is to be done and the precautions to be adopted for preventing danger and/or
injury.
5.2 Safety Programme or Switching Schedule
The Authorised Person who will be responsible for issuing of the safety documents
for all programmed work or testing on high voltage systems shall prepare in duplicate
a safety programme detailing the activities which are to be carried out.
When the safety programme has been completed it should be countersigned by
another Authorised person who has detailed working knowledge of the particular
system involved.
5.3 Safety Documents
The function of safety documents „Permit to Work‟, „Sanction for Test‟ and „Limitation
of Access‟ is to ensure that any work authorised on or in close proximity to high
voltage systems or equipment is strictly controlled.
Only one pad for each type of safety documentation shall be used.
The documentation is to be kept in a locked cabinet in the Authorised person‟s office.
A safety document must not be issued for work on any equipment which is already
the subject of any other safety documentation.
If at any time additional work is required the University Authorised person must
cancel the existing safety documentation and issue a new safety document to cover
the additional work.
The issuing and cancellation of all safety documentation is to be recorded in the
logbook.
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All completed safety documentation pads must be kept locked away in the
authorised person office for a minimum of three years from the date of the last
document issued.
5.4 Safety Equipment
Safety equipment to facilitate the safe operation and servicing of high voltage
systems should be readily available to the Authorised persons, this should include:
A mimic diagram(s) of the Universities High voltage systems
A complete set of numbered safety locks and keys.
A key safe to accommodate the appropriate safety keys whilst work is in
progress.
A log book for recording all switching operations, safety precautions, repairs
and any unusual occurrences concerning the high voltage system
Operating and maintenance manuals
A printed pad of safety documentation with serial numbers
Safety posters which should be permanently fixed in each sub-station as
follows
A poster showing an approved method for treatment of electric shock
The Electricity Safety Code of Practice for high voltage systems.
Testing, earthing equipment for the use of Authorised persons.
5.5 Security and Access to Sub-stations
All substations must be kept locked at all times and all access keys kept in a secure
key locker controlled by the Authorised Person(s).
The University operates a standard ASSA locking system „E‟ key for low voltage
electrical distribution cupboards, risers, etc. or an Onity card lock is which is used on
all access doors to these areas. In a some areas the high voltage distribution
system/equipment is within an area accessible with an „E‟ key or card and in such
cases the high voltage area has been segregated a separate ASSA „HV‟ lock and
key held only by Authorised person(s).
No person shall enter any Sub-Station containing high voltage equipment or cables
unless they are suitably authorised to do so or personally supervised by someone
who is.
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All high voltage switchgear is locked to prevent unauthorised operation or to avoid
danger. Under normal operational conditions the University Distribution System
equipment is locked using system padlocks (each substation having its own unique
Papaiz suite) to prevent unauthorised operation. The locks are only removed as and
when the system is being worked on or when the normally open points (NOP) are
being moved.
System lock keys are not to be issued with Sub-Station Access keys and must be
kept separate.
All Sub-Stations are clearly identified to match the schematic diagram to ensure the
operative has the correct location.
The University will ensure that approved rubber matting is installed immediately in
front of all high voltage switchgear within the Sub-Station.
5.6 Signs and Notices
5.6.1 Safety Signage
It is a legal requirement that all safety signs shall comply with BS5378 Part 1.
Any existing safety signage which does not satisfy the requirement must be
replaced.
A Danger of Death sign should be fixed in a prominent position outside every
sub-station and accommodation where high voltage is present.
5.6.2 Temporary Notices
Danger and Caution notices must be prominently displayed at relevant
positions before the start of any work or testing and before the issue of any
permit to work or sanction for test.
Loops used for fixing temporary notices to equipment should be purpose
designed and of a non conducting material. Temporary notices shall be fixed
to these points using cable ties.
If an approved contractor is working on the system then they shall provide all
signage as appropriate.
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6 Operation and Maintenance
6.1 Operational Procedures The following details the procedures relating to the normal operation of Plymouth
Universities High Voltage Distribution Network.
A Switching Schedule shall be prepared by the Authorised person and approved for
every switching operation involving the high voltage distribution network.
Switching shall only be carried out by an Authorised person or an Approved Contractor Senior authorised person with the appropriately completed “Authority to Operate” form.
Safety documents shall be issued by Authorised persons as required.
The works covered by the Permit to Work or the Limitation of Access will be carried out by the persons authorised by the Authoring Engineer or Authorised Person.
Safety documents will be cancelled by the Authorised person.
The high voltage distribution system shall be fully restored to the status as defined on the Switching Schedule and any Normally Open Point put back as appropriate.
Full records will be kept of all operations, Safety Documents, Switching Schedules, and Diagrams in the High Voltage files and recorded in the Logbook.
All persons carrying out work on the University‟s high voltage network shall have
written authority from the Authorised Person to do such work. In some cases it may
be operationally beneficial for the University to sign over its high voltage system to
the approved contractor and in such cases this permission may be granted by
completing the appropriate „Authority to Operate‟ form supplied by the approved
contractor.
At the time of writing the two contractors authorised to work on the University‟s high
voltage network are:
SSE Contracting Ltd - 01752 755550
Western Power Distribution - 01752 502010 or 502023
At the time of writing SSE Contracting Ltd are contracted to offer an emergency call-
out service for Plymouth University for their high voltage systems.
No person shall commence work without fully understanding the instructions received. In no circumstances shall these instructions be exceeded. Should any person consider that the instructions given cannot be carried out safely, that person has the right to have the matter referred to the University Authorised Person for a decision before proceeding. No apprentices will work on University high voltage systems unless under the
personal supervision of a qualified Authorised person.
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Whilst it is recognised that contractors cannot be constantly supervised (hence this
requirement for the operatives to be competent), the University Authorised Persons
will from time to time and without notice visit site to inspect the work.
Any locks, keys, documents, special tools etc. issued to the person carrying out the work shall be handed back to the University on completion.
No person shall interfere with any earth connections, danger notices, caution notices, safety barriers or other safety devices.
No person shall smoke in any University building, including High Voltage Sub-Stations, Low Voltage switch rooms, plant rooms, etc.
The University Designated Engineer, Authorised persons, Electrical engineers,
Safety officer or Duty holder may stop the work with any electrical system or
equipment if they are of the opinion that the Electricity at Work Regulations 1989 are
not being complied with.
Except in an emergency the electricity supplies in a building must not be isolated or
otherwise interrupted without the prior permission of Estates Services.
All Contractors attending/working on site must sign in at the Estates Contractors
office.
All Contractors working on site must be fully aware of the Site Rules and Conditions
and should have signed to confirm acceptance of the rules.
6.2 High Voltage Switching
Normal switching of the Universities high voltage switchgear shall only be carried out
by Authorised Person‟s and no such switching shall be carried by others except in
cases of emergency.
Switching of the Western Power Distribution (DNO) high voltage equipment shall not
be carried out by University staff.
The person authorising the switching shall communicate directly with the person
carrying out the switching. A switching schedule shall be produced and safety
documents issued.
Where switching will cause a temporary or complete interruption of supply to a
building(s) the Directorate/Faculties(s) affected will be notified in writing giving 30
days notice. All power outages will be co-ordinated by the Authorised person with the
users of any University buildings affected.
All safety equipment, tools, safety locks, test instruments shall be made available to
the person authorised to carry out the switching operations.
Any high voltage systems/equipment showing signs of any distress or poor condition
shall be reported to the Authorised Person‟s for a further decision/action.
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6.3 Switching Schedules
Prior to the operation of any high voltage systems, equipment, switchgear or the
issue of a Permit to Work for high voltage systems or a low voltage system, a
switching schedule must be written.
For all programmed work or tests on high voltage equipment, the Authorised person
completing the switching schedule is to have the original countersigned by another
Authorised person, the Designated engineer or Authorising engineer who has
knowledge of the particular system and installation, and access to a current
schematic diagram of that system and installation.
The Authorised person is to refer to the original of the switching schedule while
carrying out the programme and must completed and sign for each operation. The
Authorised person must not deviate from the switching schedule.
On completion of the programme, the original switching schedule is to be scanned
on to the computer and stored on the shared drive „high voltage‟ folder. The original
paper copy is to be filed in the Authorised person‟s office.
The switching schedule is to be written and is to indicate: -
the purpose of a proposed work or test
the equipment that the proposed sequence of operations will make safe
the commencement date for the proposed operations
the name of the originating Authorised person
A schematic diagram showing the specific work area to include all points of
isolation, circuit main earths that have been applied, etc.
for work or tests on high voltage equipment, the name of the countersigning
Authorised person or Authorising engineer together with the sequence of
operations proposed indicating:
the location at which each operation is to be performed
the identity of each item of switchgear to be operated
the operation to be performed
the reason for the operation
any items (e.g. keys, locks, signs) required
intended special instructions or safety measures. Where switching will cause a temporary or complete interruption of supply the building users affected will be notified in writing giving 30 days‟ notice. All power outages will be co-ordinated by the Authorised Person with the users of any buildings affected.
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6.4 Live Working Live work on high voltage conductors or equipment, including HV/LV step-down transformers, is forbidden. No person shall undertake any repair, maintenance, cleaning, alteration or any such work on any part of the University HV Network unless that part or parts of the system are:- Dead Isolated; and all practicable steps taken to lock off from all points of supply, including back-up generators and other sources from which the apparatus and conductors may become live. Caution Notices shall be fixed at all points of isolation. Earthed; by approved means at all points of isolation or between such points and the point of work. Screened; where necessary, to prevent danger. Danger Notices are to be attached to apparatus containing live conductors. Identified; at the point of work by approved means including labels, record drawings, signal injection of cables, etc. Released: at the point of work by issue of an appropriate Safety document. The document shall not be issued unless such person is fully conversant with the precise parts of the system to be worked on, the nature and extent of the work to be done and the safety precautions taken. It is the duty of the person issuing the appropriate Safety document to ensure compliance with the foregoing provisions in the correct sequence, DIESIR. It is the duty of the person issuing the appropriate Safety Document to ensure compliance with the foregoing provisions in the correct sequence.
6.5 Live Phasing Tests
Live phasing tests are to be undertaken only by the authorised persons or the
approved contractor, in receipt of an “Authority to Operate” form. A Permit to Work is
not required, but the approved contractor is to be accompanied by another person
who has adequate knowledge or experience to avoid danger, and who has been
instructed in the action to be taken in the event of an accident.
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7 Safety Documentation
7.1 Permits to Work (PTW)
A Permit is not to be issued for an item of equipment which is already the subject of
another Permit to Work or a Sanction for Test on live equipment.
Authorised persons undertaking tasks requiring Permits are to issue them to
themselves or preferably to each other.
The issue and cancellation (or loss) of every permit is to be recorded in the central
high voltage files in the dedicated Authorised person(s) Office.
A Permit to Work is to state precisely and legibly:
the location and identity of the equipment that has been made safe and
upon which the work or test is to be performed;
details of the work or test which is to be carried out;
the specific point(s) of isolation and earthing and, for a Sanction For Test, which earth(s) may be required for testing purposes;
that Caution and Danger Signs are displayed where required;
the safety locks are fitted at points of isolation;
any special instructions or safety measures;
Prior to issuing a Permit, the Authorised person is to:
Physically identify to the prospective Competent person the equipment on which the work or test is to be undertaken.
Show the prospective Competent person the safety arrangements at the points of isolation and at the places of work or test.
Draw the attention of the prospective Competent persons to any special instructions of safety measures noted in the Permit.
Demonstrate to the satisfaction of the prospective Competent person that the equipment is dead and safe to work on or test.
Prior to accepting the Permit, the prospective Competent person, having understood
the work or test to be undertaken, and being prepared to undertake it, is to initial any
special instructions or safety measures noted in the Permit, and is to sign, thus
rendering the Permit valid for the defined work or test.
The acceptance of a Permit makes the Competent person personally responsible for
directly supervising or undertaking the defined work or test. The Competent person
is therefore not to leave the working place or to undertake other work or tests while
the defined work or test is in progress. During any temporary absence of the
Competent person from the working place, the work or test is to be temporarily
suspended and adequate safety precautions taken until the work or test is resumed.
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Having completed the work or test, and having withdrawn all persons, instruments
and tools from the working place, the Competent Person is to sign, and return the
original Permit to the Authorised Person.
The Authorised Person is to check that the work or test has been completed
satisfactory and that the equipment is safe and, in a Hazardous Area, is to be
satisfied with the integrity of the explosion protected of all equipment that may have
been affected by the work. The Authorised Person is then to cancel the Permit to
Work by destroying the original and signing the duplicate retained in the pad.
7.2 Limitation of Access (LOA)
At times it may be necessary for Competent persons to enter or carry out work within
a high voltage sub-station (e.g. to test the emergency lighting or other work that does
not affect HV equipment). In such cases a Limitation of Access is to be issued to the
person carrying out the work to clearly state what it is they are permitted to
undertake and any safety precautions that need to be taken.
They are to be informed of the dangers of working in a high voltage sub-station and
are not to touch any of the apparatus. They are also to be informed that the
substation is not to be left unattended at any time. A risk assessment may be
necessary if the work is not simple in nature.
The person may be issued with the relevant high voltage sub-station key (but not the
HV master key).
No University sub-stations have any automatic fire suppression systems fitted that
need to be isolated before work can commence.
All Limitations of Access must be issued by the Authorised person at the Sub-
Station.
7.3 Sanction For Test (SFT)
The University has no high voltage test equipment.
Therefore, all testing shall be undertaken by an approved High Voltage Contractor.
The approved contractor shall be issued with an “Authority to Operate” form by the
Authorised person and upon receipt may operate switchgear and undertake testing
on behalf of the University.
Any equipment which has been isolated and earthed for testing under the terms of a
SFT shall not be connected to the system until such apparatus has passed such
tests. The recipient of the SFT shall be responsible for coordinating all testing
operations on the isolated equipment and for ensuring safety during the tests. The
recipient may remove and replace as necessary CME's and carry out tests including
making live the equipment concerned from a testing supply. Unless alternative
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procedures apply, each CME removed by the recipient of the SFT shall whenever
reasonably practicable be replaced before signing the clearance section of the SFT.
Whenever any high voltage equipment is to be subjected to test voltage before being
connected or reconnected to the high voltage system, whoever is responsible for
applying the test voltage shall ensure that such equipment and the associated test
equipment, leads and connections are adequately guarded to prevent danger and
that danger notices are attached in conspicuous positions during the test. All cables
and capacitors shall be discharged before and after the application of test voltage.
Temporary conductors used for testing shall be adequately sized and easily visible.
Where high voltage tests are to be undertaken, the areas containing exposed live
conductors, test equipment and its high voltage connections are to be regarded as
high voltage enclosures.
Safety equipment is to be provided by the Contractor and is to be readily available at
all times to those who need it. It is to be worn or used whenever necessary to avoid
danger.
Only approved safety equipment is to be used.
Safety equipment is to be inspected by the user for visible defects on each occasion
prior to use. Any suspect item is to be reported to the Authorised person who is to
consider its withdrawal and its re-provision.
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8 System Maintenance
To help ensure the high voltage systems of the University are kept in good condition
and safe working order it will be necessary to inspect and maintain it at regular
intervals. A visual inspection of all sub-stations shall be undertaken at least once
every quarter with an „official‟ annual inspection by an approved High Voltage
Contractor who is to submit a written report following the inspections together with
any recommendations. The annual inspections are to include oil samples from
transformers and switchgear, earth resistance measurements.
All oil filled switchgear shall be maintained (including renewal of oil) by an approved
High Voltage Contractor between four and six years.
All vacuum, sulphur hexafluoride gas (SF6) switchgear to be maintained in
accordance with the manufacturers‟ recommendations.
All main switches are to be operated once every 12 months by the Authorised
Person(s) using a written switching schedule.
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9 Records
A schematic diagram of each University HV network shall be kept in the AP‟s Offices
showing the present status of the networks. These schematics shall be amended
after each switching operation (if appropriate) and a record kept in the logbook of the
amendments and the date the operation took place. All switching operations shall be
committed to a switching schedule and a copy kept on the file 1130/1.
All documentation including switching schedules and safety documents must be
retained in the central files located in the dedicated Authorised Person Office in 18
Endsleigh Place:
Completely filled logbooks and safety documentation are to be retained in a lockable
cabinet in the Authorised Person Office for a minimum of three years after the date
of the last entry.
9.1 Underground Services
The University has a complex network of both high and low voltage cables installed underground on both Plymouth campuses In addition there are many other underground electrical, gas, water, data services owned by others. To ensure a safe system of work the University has produced a leaflet which is handed to staff or contractors undertaking such work.
All excavation work should be carried out in accordance with the Plymouth University
Safe to Dig Leaflet information and the HSE – HSG 47 Avoiding Danger from
Underground Services.
The Contractors/Employees required to carry out any excavation work to dig should
approach the work systematically, using plans and other positive information (e.g.
the existence of lamps and junction boxes, cable locators and safe digging
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practices). Contractors/Employees must receive adequate instructions and training
in these procedures.
Before any digging commences all RAMS must be provided to the Estates
team for approval along with the works programme 10 days prior to the start
date.
9.2 Plans
Contact Estates to obtain plans (where they are available) showing the approximate
line of known cables. The plans together with any positive signs such as junction
boxes can give a good indication of the location and configuration of cables to be
found at a particular site. It may be possible to avoid cable routes at the planning
stage of your work.
9.3 Cable Locating Devices
Trace the position of the cables as accurately as possible with a “cable locating
device” in conjunction with any available cable plans. The cable locator should
always be available for use on the site. The line of any cable should be noted and
marked (using paint, wooden pegs, waterproof chalk- but not sharp spikes). Cables
rarely follow an exact straight line.
9.4 Safe Digging Practices
Underground cables can often be found just below the surface. Even the shallowest
excavation may be a source of danger.
Once you have determined their approximate positions using plans and cable
locators, you can expose buried cables by using hand tools with care. Use spades
and shovels rather than forks or picks. Keep a careful watch for evidence of cables
during digging work and repeat checks with a cable locator.
Where practicable, do not use power tools within 0.5m of the indicated line of a
cable, and never over the line of the cable. If necessary, dig carefully by hand under
the surface to locate the cable.
If you have to break away or disturb concrete in which cables are embedded, the
cables should be made dead or an alternative safe method of excavation agreed
before work starts.
If you are in any doubt about whether an exposed service is a “live” or “dead” cable,
a water pipe or other service, treat it as a “live” cable.
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10 First Aid & Emergency Procedures
All University Authorised and Competent persons are to have attended a basic first
aid course covering effective treatment for electric shock.
Every electrical contractor on site must ensure that adequate first aid is available and
that there operatives have been suitably trained. It is sensible for all contractors to
make arrangements with the main contractor to provide first aid (if possible).
First aid arrangements will vary with the degree of risk on the site, but should usually
include as a minimum:-
a fully stocked first aid box(s)
trained first aider(s) though for small sites it is sufficient to appoint a
person to take charge of the first aid box and any situation where serious
injury or major illness occurs (responsibilities should include phoning for
an ambulance)
information for workers on site about first aid arrangements, including the
location of the nearest telephone.
In an emergency contact either Estates on Plymouth 588450 (internal
extension 88450) or the Security Operation Room on Plymouth 583333
(internal extension 3333)
The University has produced a separate Code of Practice for Emergency
Procedures.
The follow are also to be contacted in the event of a high voltage emergency or a
high voltage power outage to the University.
David Kingwell – Designated Engineer (07837 167020)
Peter Bellan – Authorised Person (07776 225545)
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Signed: …………………………………………………… Dated………………..
Chris Bunce
Acting Director
Directorate of Estates and Learning Facilities
Next Review Date – August 2013
