Western Power Plain Document · WA general workplace safety legislation administered by the...

DOCUMENT CONTROL

Document Owner (May also be the Process Owner)

Name: Mark Van Vuuren

Position: Field Practices Coordinator

Date: June 2014

Approved By *

Name: Mark Van Vuuren

Position: Field Practices Coordinator

Date: June 2014

Authorisation ** Process Owner is hereby vested with

authority and responsibility to manage the process end to end.

Name: Lance Roberts

Position: Manager Health and Safety

Date: June 2014

Date Created/Last Updated June 2018

Review Frequency *** Every 3 years

Next Review Date *** June 2021

*

Must be the Process Owner and is the person assigned authority and responsibility for managing the whole process, end-to-end, which may extend across more than one division and/or functions, in order to deliver agreed business results.

** This person will have the power to grant the process owner the authority and responsibility to manage the process from end to end.

*** Frequency period is dependent upon circumstances– maximum is 5 years from last issue, review, or revision whichever is the latest. If left blank, the default will be 1 year unless otherwise specified.

STAKEHOLDERS

The following positions must be consulted if an update or review is required:

NOTIFICATION LIST

The following positions must be notified of any authorised change:

MANAGER SAFETY AND HEALTH MANAGER SAFETY AND HEALTH

MANAGER MICROGRIDS GENERATION MANAGER ENGINEERING & PROJECTS SERVICES

ASSET MANAGER MICROGRIDS GENERATION ASSET MANAGER MICROGRIDS GENERATION

FIELDS PRACTICES COORDINATOR MANAGER MICROGRIDS GENERATION

FIELDS PRACTICES COORDINATOR

REGIONAL MANAGEMENT TEAM (RM, AM, WDC)

OPERATIONAL STAFF

HORIZON POWER

Generation Permit To Work Standards © Horizon Power DM# 10253285 Reviewed Date: June 2018

INTRODUCTION

This Generation Permit-to-Work Standard (GPTWS) provides the minimum safety

standards for activities related to inspection, testing, commissioning, operation,

maintenance and modification of generation assets. These Standards are written

to assist Horizon Power employees, contractors and other parties involved in

managing risks associated with carrying out the diverse breadth and depth of

these activities in the business.

The standards govern generation asset isolation but do not detail all of the

necessary requirements to carry out activities, but together with other procedures,

operational instructions and manuals will provide a structured safe system of

work.

The GPTWS have been written to support Horizon Power’s overall Safety and

Health Management System and the hierarchy of Acts/Regulations, Codes of

Practice, Organisational Policies, Practices and Procedures.

Hierarchy of Documentation

WA general workplace safety legislation administered by the regulator WorkSafe

WA:

Occupational Safety and Health Act 1984

Occupational Safety and Health Regulations 1996

WA Electrical legislation administered by the regulator EnergySafety WA:

Electricity Act 1945

Electricity Licencing Regulations 1991

Electricity Regulations 1947

In the interest of your own personal safety, and the safety of all Horizon Power

workers and the general public it is essential that you read these standards and

understand how they relate to your work environment.

These Standards will be regularly reviewed, if there are any queries and

suggestions for improvement, then direct your queries to the Field Practices team

via the Continuous Improvement Process.

The following diagram (the next page) outlines the framework into which these

Standards fit.

HORIZON POWER


Acts & Regulations

Codes of Practice

AS/ANZ Standards

Guidenace Notes

Horizon Power Safety & Health Management

Systems

Horizon Power Electrical Safety

Standards

Horizon Power Work Instructions

Horizon Power Switching Manuals

Horizon Power published technical

standards & guidelines

Figure 1 –Legislative/ Horizon Power framework

HORIZON POWER


CONTENTS

1 PURPOSE .................................................................................................. 1-1

2 SCOPE ....................................................................................................... 2-1

2.1 General ............................................................................................. 2-1 2.2 Isolation and Issuing Permits ............................................................ 2-1

2.3 Training and Authorisation ................................................................ 2-1

3 DEFINITIONS ............................................................................................. 3-1

4 RESPONSIBILITIES .................................................................................. 4-1

4.1 Formal Leaders ................................................................................ 4-1

4.2 Authorised Persons .......................................................................... 4-1 4.3 Permit Issuer .................................................................................... 4-1 4.4 Isolation Officer – Mechanical/Electrical ........................................... 4-2 4.5 Recipient-in-Charge .......................................................................... 4-2

4.6 Recipient........................................................................................... 4-3

5 SAFETY PRINCIPLES ............................................................................... 5-1

5.1 General ............................................................................................. 5-1

5.2 First Aid ............................................................................................ 5-1 5.3 Personal Protective Clothing and Equipment ................................... 5-1

6 ENERGY ISOLATION ................................................................................ 6-1

6.1 General ............................................................................................. 6-1

6.2 Identifying Isolation Points ................................................................ 6-3 6.3 Isolation Procedure ........................................................................... 6-4 6.4 Locking Isolations ............................................................................. 6-4

6.5 Remove Isolation .............................................................................. 6-6 6.6 Removal of Locks ............................................................................. 6-6

6.7 Isolation Tags ................................................................................... 6-7

7 PERMIT TO WORK .................................................................................... 7-1

7.1 General ............................................................................................. 7-1 7.2 Preparation of a Permit-to-Work ....................................................... 7-2

7.3 Isolation ............................................................................................ 7-2 7.4 Issuing a Permit to Work................................................................... 7-3

7.5 Storage of a Permit to Work ............................................................. 7-3 7.6 Working Under a Permit to Work ...................................................... 7-3 7.7 Relinquishing a PTW for a STT ........................................................ 7-4 7.8 Cross Boundary Permit and Lockout Requirements ......................... 7-5 7.9 Transferring Responsibility of a Permit to Work ................................ 7-6

7.10 Relinquishing a Permit to Work ........................................................ 7-6 7.11 Cancelling a Permit to Work ............................................................. 7-7

8 SUPPLEMENTARY PERMITS ................................................................... 8-1

8.1 General ............................................................................................. 8-1 8.2 Hot Work Permit ............................................................................... 8-1 8.3 Confined-Space Entry Permit ........................................................... 8-1

HORIZON POWER


8.4 High Voltage (HV) Electrical Access Permit ..................................... 8-2

8.5 Excavation and Trenching Permit ..................................................... 8-2 8.6 Sanction-to-Test (STT) Permit .......................................................... 8-2

8.7 Operating Agreement ....................................................................... 8-3

9 REMOTE SITE PERMIT TO WORK REQUIREMENTS ............................. 9-1

9.1 General ............................................................................................. 9-1 9.2 Preparation of Permit to Work .......................................................... 9-1 9.3 Equipment Preparation – Isolate ...................................................... 9-2

9.4 Issuing a Remote Site Permit to Work .............................................. 9-2 9.5 Working Under a Remote Site Permit to Work ................................. 9-2 9.6 Cancelling a Permit to Work ............................................................. 9-2

10 APPENDIX SECTION .............................................................................. 10-1

10.1 Appendix A – Isolation Philosophy ................................................. 10-1 10.2 Appendix B - Permit to Work Flow Diagram ................................... 10-1 10.3 Appendix C – Associated GPTWS links ......................................... 10-1

HORIZON POWER SECTION 1 Page 1-1


1 PURPOSE

This standard encompasses instructions necessary for safe access to Generation

Assets within Horizon Power’s generating systems and fuel facilities to ensure safety of

generation assets and personnel from the dangers related to hazards or unauthorised

operation.

The instructions explained in this Standard are the minimum required to ensure the

safety of personnel and plant.

This Standard has been prepared to address all of Horizon Power’s generation assets

and has specific inclusions to cater for remote locations where a single person is likely

to be working alone.

The Standard has been developed to cover the following key processes:

Permit to Work

Supplementary Permits

Isolation(s)

Remote Site Authorisation

Where Horizon Power have sites located within the boundaries of other organisations or

where it operates through established Alliance or Joint Venture arrangements the

requirements of this standard shall be applied as the minimum standard.

SECTION 1 HORIZON POWER Page 1-2


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2 SCOPE

2.1 General

These standards shall apply to all persons who work on or near Horizon Power’s

generation assets.

This standard applies where inspection, testing, commissioning, operation, maintenance

and modification activities are carried out on generation assets.

This Standard applies to:

generation assets owned and/or controlled by Horizon Power, or

generation assets owned or controlled by contractors or others where the plant is

located on premises owned by Horizon Power

the boundary of the Power Station shall be the output bushings of the step up

transformer or the supply side of a feeder circuit breaker if there is no step up

transformer

This standard does not apply to:

where there is no risk to the safety of person(s) and or generation asset integrity

a construction site that has no potential to be connected to any operational

generation asset(s)

2.2 Isolation and Issuing Permits

The isolation of generation assets and the issue of permits is a restricted duty. Only

Horizon Power authorised persons are allowed to make equipment isolations and issue

permits.

2.3 Training and Authorisation

Persons who are required to work on Horizon Power’s generation assets shall not do so

unless they:

have been appropriately trained for the work they intend to do;

have the appropriate authorisation to perform the work

To maintain authorisation, refresher training in the GPTWS shall be undertaken at

regular intervals (every 2 years). The minimum knowledge and skills necessary to

perform specified activities and tasks will be assessed. Refresher training may be

carried out on the work site.

Field Practices Safety Interaction Audits will be carried out in a scheduled manner to

audit against generation related instructions.



3 DEFINITIONS

Terminology Definition

Approved Having the appropriate organisation endorsement in

writing for a specific function.

Authorised Person A person with technical knowledge or sufficient experience

who has been approved, or has the delegated authority to

act on behalf of Horizon Power to perform the task

concerned

Circuit Breaker Circuit Breaker shall mean an item of electrical apparatus

designed to de-energize an electrical system under

conditions of load and/or fault.

Control Lock (Blue)

An individually keyed Blue Lock that is attached by an

Authorised Person to further secure a Lockbox and

provide protection for the generation asset and personnel.

Danger Tag

A tag applied in conjunction with a Personal Lock to

identify an individual who is working under the conditions

of a Permit-to-Work.

Only the person whose name appears on the Danger tag

can remove the tag.

Earthed Earthed shall mean electrical apparatus, which has been

electrically connected to earth effectively, ensuring an

immediate and continuous discharge of electrical energy.

Energy Isolation The point at which an energy source (electrical only) is

disconnected or physical blocked and secured from

uncontrolled movement to ensure safety of personnel and

the generation asset.

Formal Leader An individual appointed by Horizon Power who is

accountable for implementing the safety activities

necessary to achieve safety for persons, environment and

the generation asset, within and across defined

boundaries.




Generation Asset For the purpose of this standard means any plant or

equipment used in the production and or generation of

electricity i.e. electrical, electronic, SCADA, control,

mechanical, liquid, gas, instrumentation, and

communication, etc.

High Voltage (HV) Where voltage exceeds 1000 volts alternating or 1500

volts direct current.

Hot Work Means using welding, flame cutting or other fire or spark-

producing power tools.

HV Switching

Officer A person authorised to carry out HV switching operations

within their limits of authority on generation assets.

HV Switching

Operation Any physical operation required to energise, de-energise,

or earth HV apparatus or any other device used in

accordance with an authorised Switching Programme.

HV Isolation Lock

(Black)

An individually keyed Black that is attached by a HV

Switching Officer to secure a Lock-out on HV equipment.

Isolation Lock

(Yellow)

An individually keyed Yellow lock that is attached by an

Isolating Officer to secure a Lock-out (other than HV

isolation) e.g. Mechanical isolation or Low Voltage (LV)

electrical isolation.

Isolation Officer A person authorised to isolate generation assets (other

than HV unless authorised) to be worked on under a

Permit-to-Work.

Isolation Tag

A tag installed by the Isolating Officer/HV Switching Officer

that contains Permit to Work information.




Job Risk

Assessment (JRA)

(DM# 3104177)

Before any work starts, a JRA is carried out to identify any

hazards and ensure their associated risks are either

eliminated or suitably controlled in accordance with

Horizon Powers minimum standards.

Lockbox

A safety device used to contain the keys of Isolation Locks

associated with a Permit-to-Work. Lockboxes shall have

the means of being able to be secured by Control (Blue),

Isolation (Yellow) and Personal Locks (Red).

Lock-out A device placed as a means of physically securing and

identifying isolation and/or control measure placed for

safety. A Lock-out generally consists of a keyed lock and

Isolation Tag or Danger Tag.

Lockout Hasp

To be used in conjunction with an Isolation Lock to allow

the fitting of multiple locks.

Mechanical

Isolation The point at which an energy source (Gas, Fuel, etc) is

disconnected or physical blocked and secured from

uncontrolled movement to ensure safety of personnel and

the generation asset.

Operating

Agreement (OA) An “OA” is a statement outlining the condition of

generation asset(s) that shall be used between operating

authorities across operational boundaries to confirm asset

conditions and isolations to support an access authority or

other operational requirements.

This statement covers only the state of the generation

asset(s) specified and does not by itself authorise work on

the electrical apparatus or plant.

Operational Area Any generation store warehouse, compound, power

station, workshop, switchyard, switch room or enclosure.

Operational Work Any construction, testing and commissioning, inspection,

maintenance (e.g. cleaning), fault finding, operating activity

or decommissioning on or near generation assets

including HV Switching.




Permit Board A board where the Permit-to-Work and any Supplementary

Permits are prominently displayed whilst permits are open.

Permit Issuer An Authorised Person appointed to prepare, issue, transfer

and close a Permit-to-Work, Supplementary Permits or

other authority to work and all associated documentation

Permit Requestor Any person wishing to schedule or perform work that

requires a Permit-to-Work to be issued prior to the

commencement of the work.

Permit-to-Work

(PTW)

A formal written authorisation which allows access to, work

on or near, or testing of generation assets. It details the

isolation(s) and control(s) implemented to make the

generation asset safe.

Permit-to-Work

Register A register that contains a sequence of PTW numbers for

all issued, cancelled and future permits.

Personal Lock

(Red)

An individually keyed Red Lock that is attached as an

additional Lock-out by the Recipient-in-Charge and

Recipient(s) to further secure Lockouts made in the

preparation of the Permit-to-Work.

Remote Site Horizon Power sites that are operated and maintained by

single person.

Remote Site

Authorisation The issuing of a Permit-to-Work by the Permit Issuer to an

Authorised Person completing work in a Remote Site

location.

Recipient A person or group of persons performing work under a

Permit-to-Work.

Recipient-in-Charge An Authorised Person who accepts the conditions of a

Permit-to-Work and is responsible for the work being

carried out by a Recipient under the Permit-to-Work.

Safety Document Any safety related document such as Permit-to-Work,

JRA, Safety Case, Safety Management Plan, Procedure,

Work Instruction, etc.




Single Point

Isolation

An activity that is performed where a single isolation

protects or supplies generation asset.

Standard Isolation Generation site specific pre-defined isolation procedure for

generation assets.

Supplementary

Permits

Additional permits used to support a Permit-to-Work. They

are used for activities such as Confined Space Entry,

Excavation, Hot work, HV Access, Sanction-to-Test and

other high risk activities.



4 RESPONSIBILITIES

The following responsibilities are set for Horizon Power and Contractors working on

Horizon Power Assets. Horizon Power personnel and contractors have a requirement to

ensure they are trained, have read, understood and comprehend the Horizon Power

GPTWS requirements at the time of their induction.

Once training is completed it is the responsibilities of all personnel to be appropriately

authorised (see section 2.3).

4.1 Formal Leaders

It is the responsibility of the Formal Leader to ensure:

that the GPTWS are applied without compromise to ensure the safety of all

personnel working on Horizon Power’s generation assets

the instructions and procedures contained in this standard are read, understood

and complied with

employees are trained and authorised to perform the assigned tasks.

they correct the behaviour of employees who fail to follow the instructions and

procedures contained in this standard

4.2 Authorised Persons

It is the responsibility of the Authorised Person to:

comply with the instructions and procedures contained in this standard

practice safe behaviour

perform Job Risk Assessment(s) (JRA) for each new task or as jobs change

actively work with the Formal Leader to support implementation of safety

programmes

Authorised Persons will ensure the GPTWS and all related procedures are applied

without compromise to ensure the safety of personnel from hazards.

4.3 Permit Issuer

It is the responsibility of the Permit Issuer to:

comply with the instructions and procedures contained in this standard

define the isolation and/or control measure(s) of the Permit-to-Work (PTW) in

accordance with the instructions and procedures contained in this standard

ensure that Recipient-in-Charge acknowledges the PTW conditions and the

isolation and control measure(s) before the issuing the PTW



correct the behaviour of a Recipient-in-Charge who fails to comply with the

conditions contained within the PTW

4.4 Isolation Officer – Mechanical/Electrical

It is the responsibility of the Isolation Officer to:

undertake isolations of generation assets (only if authorised) in accordance with

the instructions and procedures contained in this standard

perform JRA(s) for each new task or as jobs change

4.4.1 Mechanical and Low Voltage (LV) Switching Officer

It is the responsibility of the Mechanical/LV Switching Officer to:

only undertake mechanical isolations within their limits of authority on generation

assets

only undertake LV switching operation within their limits of authority on

generation assets

4.4.2 High Voltage (HV) Switching Officer

It is the responsibility of the HV Switching Officer to:

undertake HV switching operations within their limits of authority on generation

assets

4.5 Recipient-in-Charge

It is the responsibility of the Recipient-in-Charge to:

accept responsibility as the person in charge of the work.

comply with the instructions and procedures contained in this standard.

agree to the conditions of the PTW.

ensure the Recipient(s) complies with the conditions contained within the PTW.

ensure that all Recipient(s) sign on and off the Permit-to-Work as required.

correct the behaviour of a Recipient who fails to comply with the conditions

contained within the PTW.

ensure a Job Risk Assessment is completed with each permit or as jobs change.

ensure that when transferring a PTW the incoming Recipient-in-Charge

acknowledges the PTW conditions and the isolation and control measure(s) of

the PTW.



4.6 Recipient

It is the responsibility of the Recipient to make sure that they:

comply with the instructions and procedures contained in this standard.

do not commence any work on any generation asset without a PTW issued by a

Permit Issuer.

comply with the conditions of the PTW.

do not interfere with any control, HV isolation, Isolation or Personal lock(s) or

safety isolation and control device placed in association with a PTW.

practice safe behaviour.

are involved in Job Risk Assessment for each task or as work conditions change.

actively work with their Formal Leader to support the implementation of safety

programmes.



5 SAFETY PRINCIPLES

5.1 General

All generation assets shall be regarded as operational until isolated.

A PTW shall be issued before any work starts on any generation asset.

All relevant instructions, procedures and conditions contained in a PTW shall be

complied with when carrying out any work activity in any operational area.

Hazards shall be identified and the associated risks assessed and controlled

prior to working on any generation assets.

The GPTWS shall be regularly audited to ensure compliance.

All incidents which has or could have caused personal injury or damage to

property shall be reported to the Recipient-in-Charge and the Formal Leader

immediately.

The safe approach distances to electrical apparatus for persons, vehicles and

plant shall be adhered to at all times.

5.2 First Aid

All personnel who work in Operational Areas or undertake Operational Work

must be trained in First Aid.

5.3 Personal Protective Clothing and Equipment

All personnel who work in Operational Areas or undertake Operational Work shall

wear approved personal protective clothing and equipment in accordance with

Horizon Power Minimum Personal Protective Clothing and Footwear Standard

and the appropriate Safety field instruction in the Horizonpower Instruction

Manual (HIM).

Approved Personal Protective Equipment (PPE) specified for the task or work

area shall be worn.



6 ENERGY ISOLATION

This section describes, what energy isolations are, how to prepare generation assets,

use locks, other control measures and tags to ensure the isolation(s), once made, are

adequately identified, de-energised, flow stopped, locked and/or physically restrained to

prevent inadvertent operation of the generation asset(s).

6.1 General

Isolations and/or controls are required where the work is to be carried out on generation

assets where personal and/or generation asset protection is required. Additionally,

isolation and/or control measures are required where stipulated in any other work

instruction, procedure or manufacturer requirement (e.g. Permit-to-Work, JRA, Safety

Case, Safety Management Plan, Non-routine Procedure, etc.).

All isolations shall only to be carried out by an authorised Isolation Officer or HV

Switching Officer.

All isolation and control measures placed as part of PTW shall be arranged and

managed by the relevant Permit Issuer responsible for approving the isolation(s) and

issuing a PTW.

All persons on site are responsible for complying with the requirements of all PTW

conditions, as unauthorised removal of any Lockout or safety device may result in

serious injury or death, equipment or environmental damage.

An Electronic Control System (e.g. Programmable Logic Controller, SCADA System) or

emergency stop/off switches shall not be used as the isolation and/or control point.

Horizon Power’s PTW isolation and/or control process is included at Appendix A.

6.1.1 Type of Energy isolations

Energy Isolation can be classed into two main categories, that being:

Mechanical Energy Isolation and

Electrical Energy Isolation.



Mechanical Energy Isolation

Mechanical energy can be in the form of Liquids, Gases and Vapours. There are many

way in which mechanical energy can be isolated, such as:

close a block valve to prevent flow and venting, draining or depressurising the

isolated section,

fix a blanking device to a pipe to prevent flow

disconnect a pipe to prevent flow, and

open a bleed valve to vent gas or drain liquid

Blanking devices (blinds, spades & caps) shall be designed and rated for the system. All

valves used as isolation and/or controls are required to be secured and locked and

tagged.

Where the energy source is a liquid or gas that may enter a confined space, it is

recommended to remove a pipe spool between the source and Confined Space then

blank off the energy source prior to entry.

Electrical Energy Isolation

There are two main reasons for electrical energy isolations, that being, 1) Isolation to

allow access to the driven machinery for non-electrical work and 2) Isolation to allow

access to the normally energised plant for electrical work.

Electrical energy will be classified as either Low Voltage (LV) or High Voltage (HV). LV

is where voltage exceeds 50 volts (alternating Current) and less than 1000 volts

(alternating current). For direct current the limits are between 120 volts and 1500 volts.

High voltage is where voltage exceeds 1000 volts alternating current (a.c.) or 1500 volts

direct current (d.c.).

Isolation of equipment for electrical work is to be carried out by an authorised electrical

person or authorised licensed electrical worker.

Note:

Single block, double block and bleed valves shall not be relied upon as a form of isolation for Confined Space entry.

Additional tags shall be attached to access covers removed to provide entry and ventilation to ensure they stay removed.



6.2 Identifying Isolation Points

The Permit Issuer is responsible for identifying isolations that are necessary to access

generation assets to undertake work activities. Isolation and/or control points for a

particular generation asset or part thereof can be identified by the following means:

review of the appropriate piping and instrumentation diagram (P&ID)

review the appropriate electrical schematics

review of the appropriate operating or manufacturers instruction manual

review with the Operator

performing system walk downs/visual observations

In all cases, verify that the drawings and information used for the purpose of identifying

isolations accurately reflect the current configuration of the generation assets.

Checks shall also be undertaken to identify potential back feeds, reverse flows and

interaction with adjacent equipment.

Should cross boundary isolations be identified by an Isolation Officer or HV Switching

Officer, the owner of the relevant equipment shall be contacted so that the interfacing

isolations can be arranged and managed using an Operating Agreement.

Where standard isolation procedures exist these should be carefully checked each time

they are used to verify their accuracy prior to use. Where HV electrical isolations have

been identified, a HV Switching Programme shall be completed.

A HV Switching Programme is a logical sequence of events which shall be followed to

isolate the HV electrical system and shall be used to make specific electrical

apparatus:-

de-energised prior to work commencing

energised following completion of work

supplied by different incomers and/or distribution feeders

Note:

Switching programmes for known situations which have been checked and

approved by a HV Switching Officer must be verified by a second authorised

person on each occasion prior to use to ensure that conditions regarding the

equipment and drawings have not changed.



6.3 Isolation Procedure Requirements

To effectively isolate, control or restrain generation assets or block access to an

operational area the Isolation Officer and/or HV Switching Officer shall, by using

approved safe methods, ensure that:

the equipment is shut down or de-energized

all sources of energy are isolated

the isolation is tested and proved.

isolation and/or controls are secured with Isolation Locks and tags.

Release the potential stored energy of springs when applicable.

identify and isolate automatic operation of the generation asset(s).

6.4 Locking Isolations

Where generation assets are isolated, the isolation and/or control measure shall

physically restrain from movement, locked out and identified.

All keys to Isolation Locks shall be placed in a Lockbox and secured with a Control

Lock.

A Personal Lock shall be applied to the Lockbox by the Recipient-in-Charge and

Recipient(s) to provide additional security and prevent access to the Isolation Keys.

All Personal Locks shall also be fitted with a personal Danger Tag to identify the owner

of the lock.



Isolation

Lock Keys

Lockbox 1

Isolation

Lock Keys

Lockbox 2

Isolation

Lock Keys

Lockbox 3

PTW 1

PTW 2PTW 4

PTW 3

FactoryIsolate Lock & Tag

Equipment/System

Permit Board

Figure 2 – Cascade Isolation Arrangement

The Permit Issuer may waive the use of a Lockbox for Single Point Isolations. In this

case a multi lock hasp shall be used to facilitate the application of the Recipient-in-

Charge and Recipient(s) personal Locks on the same single isolation and/or control

point. (Refer to Figure 3). The Permit Issuer shall retain the isolation lock key.

FactoryIsolate Lock & Tag

Equipment/System

Figure 3 – Single Point Isolation



6.5 Remove Isolation

Before Lockouts are removed from isolation and/or control points to enable energy to be

restored to the generation assets, the following sequence shall apply:

inspect the area to ensure that non-essential items have been removed, the

equipment components are intact and the generation asset(s) is operationally

ready.

check the work area to ensure all personnel are clear

ensure PTW and Supplementary Permits issued for the work have been signed

off and cancelled.

remove all Isolation Locks from the isolation and/or control points and return the

generation asset to its normal operating status.

record the isolation and/or control removal on the relevant Permit-to-Work

6.6 Removal of Locks

All locks placed shall be unlocked with the dedicated key for that lock.

6.6.1 Person or Key Missing

Where the person or dedicated Personal or Isolation Lock key cannot be found and the

Isolation Lock is required to be removed, the lock can only be removed by the Formal

Leader once the following steps have been taken:

all personnel protected by that lock are identified and notified.

the environment protected by the lock is proved safe.

the asset protected by the lock is proved safe.

the missing person is notified and not expected to return to site.

search for the dedicated key is unsuccessful.

Note:

It is recommended that the de-isolation is done in reverse order to prevent introducing a

hazard prior to the completion of the de-isolation.



6.6.2 Emergency

Where an emergency requires the overriding of any lock, the relevant lock may only be

removed by the Formal leader once the following steps have been taken:

all personnel protected by that lock are identified and notified, and

the environment protected by the lock is proved safe, and

the asset protected by the lock is proved safe.

In all cases where a lock is removed by force, the “Emergency Lock Removal” form

shall be completed and filed with the PTW.

6.7 Isolation Tags

The Isolation Officer shall place an Isolation Tag on all isolation and/or control points

and identify and record the necessary PTW or Supplementary Permit details on the tag.

As a minimum each Isolation Tag shall list PTW number (if applicable), equipment ID

and/or brief equipment description, Isolation Officer name and contact details, date and

time of isolation.



7 PERMIT TO WORK

This section describes how to prepare issue, accept, work under, transfer, suspend,

relinquish cancellation and close a PTW and Supplementary Permits. The PTW flow

diagram are shown in Appendix B.

A Permit-to-Work is not required for:

Routine testing, inspection or fault finding work that does not require Isolation

and/or Control.

People undertaking ground maintenance activities in a non-hazardous location of

Horizon Power generation site.

Some supplementary permit(s) may still be required to comply with the Safety and

Health Management System.

7.1 General

A PTW is an authorisation to do work. An integral function of the PTW process is to

record all isolations and other controls that are required to perform the work safely. A

PTW is required at all times where:

isolation and/or control of a generation asset are required to carry out a work

activity.

operational work is carried near a generation asset, i.e. excavation work.

where work is to be performed of a hazardous nature or in a hazardous location.

when stipulated in any other Horizon Power document. (Safety Case, Safety

Management Plan, JRA, Non-routine Procedure, etc.)

A person working under the authority of a PTW shall be responsible to carry out that

work under the conditions contained in the work permit.

In addition to a PTW, Supplementary Permits are also required for specific high risk

activities or specific activities in hazardous locations. Supplementary Permits are used

for the following:

Confined Space Entry.

Hot Work in hazardous areas.

Excavation and Trenching.

Sanction-to-Test.

HV Electrical Access.

Operating Agreement (OA).



7.2 Preparation of a Permit-to-Work

A PTW including Supplementary Permits may only be completed and issued by a

Permit Issuer.

On request for a PTW, the Permit Issuer shall prepare the PTW, Supplementary

Permits (where required) and organise for an Isolation Officer and/or HV Switching

Officer to undertake the necessary isolations and provide any special controls.

The generation asset(s) to be worked on and the scope of work are to be recorded on

the PTW. No work outside of the defined PTW scope of work will be allowed.

Identify the isolations required to safely perform the work in accordance with the

Isolation requirements described in Section 6 of this procedure.

Record the identified isolation and/or controls (with generation asset item description

and tag number whenever possible), the number of the Lockouts used and the safe

position of each point of isolation in section 3 of the Permit-to-Work. Where there is

insufficient space an Isolation Continuation Sheet shall be completed and attached to

the Permit-to-Work and indicate this on the PTW. (An Isolation Continuation Sheet is an

extension of Section 3 of a Permit-to-Work).

7.3 Isolation

The Isolation Officer or HV Switching Operator shall carry out the isolations and update

the relevant column in section 3 of the Permit-to-Work for that isolation to indicate that it

has been applied.

Where HV isolations are required, a HV Switching Operator must complete a HV

Switching Programme. These HV isolations shall be indicated in Section 3 of the PTW.

A copy of the HV Switching Programme shall be attached to the PTW.

Where Supplementary Permits are required to facilitate additional safe conditions,

update Section 4 of the PTW as the circumstance requires, identifying the type of

Supplementary Permit and its number.

The Isolation Officer or HV Switching Operator shall apply the Blue Control lock with an

Isolation Tag to the associated Lockbox. (Note: Except for a single person remote site

the Isolation Officer and HV Switching Operator can also be the Permit Issuer)

The Permit Issuer shall verify that all of the required isolation and/or control measure(s)

have been established in the field and recorded on the specific permit. After the permit

conditions have been verified the Permit-to-Work is ready for issue.



7.4 Issuing a Permit to Work

The Permit Issuer shall always ensure that Recipient-in-Charge acknowledges the PTW

conditions and the isolation and/or control measure(s) before issuing the PTW.

The Isolation officer/HV switching officer shall:

Place the keys for all HV and/or Isolation Locks in the relevant Lock Box and lock

the Lockbox with a Control Lock.

And record the following in Section 5 of the PTW:

the date and time the PTW was issued

the date and time to which the PTW can remain valid

Issuer Name, sign and date the PTW.

The Recipient-in-Charge shall sign the Permit Acceptance section of the

Permit to Work.

The PTW, Supplementary Permits and associated paperwork shall be handed over to

the Recipient-in-Charge for ongoing control until relinquished for Cancellation back to a

Permit Issuer.

7.5 Storage of a Permit to Work

The Recipient-in-Charge shall place all documentation on the Permit Board located

adjacent to the associated Lock Box.

7.6 Working Under a Permit to Work

Where a single person signs as the Recipient-in-Charge of a PTW, they will accept

responsibility for the PTW and will not work outside of the conditions and the isolation

and/or control measure(s) of the PTW.

Where a person signs as the Recipient-in-Charge of a PTW in a work group of

Recipients, they accept the responsibility as the person in charge of the work.

Note:

Without signatures in the Permit Issue and Permit Acceptance sections, the PTW

is invalid.



The Recipient-in-Charge shall be responsible for:

Ensuring that all Recipient(s) are fully aware of the conditions, the isolation

and/or control measure(s) of the PTW, and

All members sign onto the PTW.

The Recipient-in-Charge shall actively monitor the Recipient(s) activities to manage

overall safety.

Additional isolations are permitted to be added to the PTW only after agreement

between the Recipient-in-Charge, the Permit Issuer and Isolation Officer.

Where additional isolations are agreed, the details of the additional isolations must be

recorded on the PTW and any working copy. All Recipient(s) must be informed of the

additional isolation(s).

All Recipient(s) who have signed onto a PTW shall attach a Personal Lock to the

Lockout Hasp on the Lockbox associated with their PTW.

Personal Locks shall only be placed in accordance with the provisions of the PTW

Isolation Procedure in Section 6 of this standard.

Persons who are required to permanently leave the work site cannot do so without firstly

signing off the PTW and removing their Personal Lock and Danger Tag from the

Lockbox. This is to ensure that if the work is completed in their absence the PTW can

be signed off as complete and cancelled.

Any person, who leaves the site without signing off a PTW or without removing their

Personal Lock, will be required to return to the site to do so.

Where such persons cannot be found or brought back to site, the Emergency Lock

Removal steps outlined in Section 6.6.1 of this standard are to be followed.

7.7 Relinquishing a PTW for a STT

The STT shall be initiated by the Recipient-in-Charge and in conjunction with a Permit

Issuer. Although the STT Recipient-in-Charge is generally in charge of the test, the

Permit Issuer is responsible for ensuring the equipment being tested is in an adequate

state prior to issuing a STT Permit.

This adequate state prior to the issuing of the STT Permit, the Permit Issuer shall

ensure that:

All plant and equipment is clear of the Worksite,

All supplementary permits have been relinquished.

All person(s) working under the PTW have been withdrawn and signed off the

PTW



All necessary guards and protective devices have been replaced where possible.

The generation asset or part thereof is ready for testing or adjustment, and

The Isolation Officer shall record all Isolation and/or Control measures that have

been removed on the PTW.

Permit Issuer issues the STT Permit to the Recipient-in-Charge.

If work under the PTW needs to continue on completion of the test(s) or adjustments,

Section 8 of the STT Permit form shall be completed and the Permit Issuer shall

arrange for the Isolating Officer to have all isolations re-instated, recorded on the PTW

and verified to comply with the PTW.

The Permit Issuer will reissue the PTW and all Recipient(s) are to re-sign the PTW.

If the test or adjustment is completed and the job is complete, the STT Permit and the

PTW may be signed off as cancelled and closed together, with the Generation Asset(s)

being returned to service.

7.8 Cross Boundary Permit and Lockout Requirements

Where an external operator has requested isolations within the generation boundary the

following shall apply:

The Permit Issuer shall prepare the Operating Agreement (OA) and arrange for

an Isolation Officer or HV Switching Operator to undertake the isolations and/or

controls.

The Isolation Officer shall undertake the required isolations in accordance with

the GPTWS standard.

The Issuing Officer shall issue an OA to the external operator’s Recipient-in-

Charge.

The external operator OA Acceptor shall check all isolations prior to accepting

the OA.

The external operator’s OA Acceptor shall place their Personal Lock to the

Lockbox to provide additional security and prevent access to the Isolation Keys.

Note:

If the test or adjustment involves HV isolations, then only an Authorised HV

Switching Officer may perform the task under the STT Permit.



On completion of the task the OA shall be cancelled in accordance with the GPTWS

standard.

The external operator’s OA Acceptor shall remove their Personal Lock in accordance

with the GPTWS standard.

7.9 Transferring Responsibility of a Permit to Work

The PTW may be transferred to another Recipient-in-Charge by completing Section 10

of the PTW.

The departing Recipient-in-Charge must notify the Permit Issuer of the change

before transferring the PTW.

The departing Recipient-in-Charge shall always ensure that the incoming

Recipient-in-Charge acknowledges the PTW conditions and the isolation and/or

control measure(s) before transferring the PTW.

The departing Recipient-in-Charge must remove their Personal Lock and Danger

Tag from the Lockbox.

If the permit transfer section is not fully completed, the PTW is invalid.

7.10 Relinquishing a Permit to Work

The Recipient-in-Charge is responsible for ensuring that all Recipient(s) have exited the

work area, that the work has been completed and that the generation asset is ready to

be placed back into service.

All Recipient(s) are required to have signed off the PTW and any Supplementary

Permits, and then remove their Personal Locks from the Lockbox. (This includes the

Recipient-in-Charge removing their lock(s) if placed).

The PTW and any Supplementary Permits may be relinquished by the Recipient-in-

Charge by signing the appropriate section of the Supplementary Permit(s) and Section

7 of the PTW.

The PTW and Supplementary Permits shall be removed from the Permit Board and

returned to the Permit Issuer for closure and record keeping.



7.11 Cancelling a Permit to Work

The Permit Issuer must ensure that the PTW and any Supplementary Permit(s) have

been completed in accordance with this GPTWS standard.

The Permit Issuer shall instruct an Isolating Officer to remove the isolation and/or

control measure(s) placed in association with that PTW.

The Isolating Officer shall initial/sign the “Remove” column in Section 3 of the PTW to

confirm that the isolation and/or control measure(s) have been removed.

The Isolating Officer shall return the PTW form and associated Supplementary Permits

including all Isolation Tags to the Permit Issuer.

The Permit Issuer may then sign the permit cancellation section of the PTW, and file all

documentation for record keeping and auditing.



8 SUPPLEMENTARY PERMITS

8.1 General

Supplementary Permits (7.2 – 7.7) are an authorisation to do specific activities and are

used to record the additional controls specific to the high risk tasks they are associated

with. Refer to other Horizon Power procedures for additional instruction for the high risk

activity the Supplementary Permits are provided for.

Where Supplementary Permits are required they shall be issued, accepted, relinquished

and cancelled using the same process as a PTW.

Supplementary Permits shall only be issued in conjunction with and referenced on the

PTW. If a PTW is cancelled in accordance with 6.10, the Supplementary Permit must be

cancelled at the same time.

8.2 Hot Work Permit

A Hot Work Permit is required where hot work is to be carried out on or near any

generation asset(s) in hazardous zones or where identified by the Permit Issuer.

Hot work may include but is not limited to:

Use of mobile phone, cameras, power tools and other non-intrinsically safe

equipment.

Use of all forms of electric/gas welding and cutting processes.

Operating plant and machinery driven by a combustion engine.

Use of tools that generate a spark during impact or use.

Any vehicle and equipment that may generate an ignition source.

8.3 Confined-Space Entry Permit

A Confined-Space Entry Permit is required where persons are required to enter into any

declared Confined Space.

The definition of a Confined Space in AS 2865 is any enclosed or partially enclosed

space that is not intended or designed primarily for human occupancy, within which

there is a risk of one or more of the following:

An oxygen concentration outside the safe oxygen range.

A concentration of airborne contaminant that may cause impairment, loss of

consciousness or asphyxiation.

A concentration of flammable airborne contaminant that may cause injury from

fire or explosion.

Engulfment in a stored free-flowing solid or rising level of liquid that may cause

suffocation or drowning.



8.4 High Voltage (HV) Electrical Access Permit

The HV Electrical Access Permit is designed to be used by personnel who are required

to access HV Electrical Generation Assets.

No Horizon Power employee or authorised contractor shall work on HV electrical

apparatus which is energised or is capable of being energised.

Access is permitted only after the electrical generation assets have been isolated,

proved de-energised, earthed by approved methods, locked where practicable and

danger or isolation labels fitted.

8.5 Excavation and Trenching Permit

The Excavation Permit is designed to be used by personnel who are required to carry

out excavations or trenching where there is a risk of damage to underground generation

assets.

A site survey must be undertaken to identify if there are any buried services prior to any

excavation work being undertaken.

All buried generation asset(s) shall be identified, located, proved and where possible

isolated.

Where generation asset(s) have been identified an Excavation and Trenching Permit

will be required.

All buried Generation Asset(s) and their controls shall be recorded on the Excavation

and Trenching Permit.

An excavation or trench by virtue of other hazards may also be classified as a Confined

Space. This is generally as a result of atmospheric contamination, engulfment, flooding

etc.

Where the excavation or trench is classified as a confined space, a Confined Space

Entry Permit will be required by personnel required to enter these excavations.

8.6 Sanction-to-Test (STT) Permit

The STT Permit is designed to be used by personnel who are required to test new,

reconditioned or existing generation assets on which tests are to be conducted.

A STT is required when, in order to complete the work described in the PTW, the

release of one or more isolation and/or control measures by an Isolating Officer is

required so that energy supplies can be used to complete the test or adjustment.

The STT allows access to generation assets for the fitting, operating and removal of test

devices.



Any alterations to the manner in which the generation assets have been isolated are

permitted only with the knowledge and approval of the Permit Issuer, who may give

written instructions on the STT.

The STT cannot be issued in conjunction with an HV Electrical Access Permit for the

same apparatus, as the testing procedure may require a voltage to be applied.

8.7 Operating Agreement

An Operating Agreement (OA) is an agreement between two Operating Authorities, for

example, Horizon Power as a generator and Horizon Power as a network operator or an

Independent Power Producer (IPP) as a generator and Horizon Power as a network

operator.

It is used to confirm that an electrical apparatus operational state will be held in an

agreed state until the OA is cancelled. An OA is used when one party needs to work on

an item of plant or electrical apparatus which requires isolation and/or earthing from an

adjacent Operating Authority.

The Operating Agreement recipient shall verify the isolations and earthing points stated

on the Agreement, and may apply additional locks and tags. An OA is not a work permit.

It does not authorise work to be undertaken. A work permit must be issued to allow work

to take place. The conditions stated on the work permit must reference the OA. An OA

is issued by a switching operator.

For standard outages, the outage requestor will write the associated switching program,

unless otherwise agreed. For the commissioning of other Operating Authority

apparatus, Horizon Power will usually write the switching program. The issue and

relinquishment of Operating Agreement must be recorded as steps in the switching

program.

Note:

Only the minimum number of Isolation Locks and / or HV Isolation Locks shall be removed to conduct the required test or adjustment.



9 REMOTE SITE PERMIT TO WORK REQUIREMENTS

9.1 General

Typically Horizon Powers’ generation assets at remote sites are maintained by single

person operators thus making the issue and receipt of Permits difficult. To cater for sites

that are operated and maintained by a single person, the PTW will be issued and

authorised from a Horizon Power representative.

The Horizon Power representative issuing a PTW from the District (not at Generation

site) shall be a Permit Issuer.

A PTW can be issued and authorised by phone (refer to Section 5 of the PTW form).

All isolations at the remote sites are to be carried out in accordance with this GPTW

standard.

Persons accepting a PTW, preparing equipment and undertaking isolations and/or

control measures at remote sites shall be trained and authorised to undertake isolations

and HV switching operations.

9.2 Preparation of Permit to Work

The remote site operator shall complete Sections 1, 2 and 4 of the PTW form listing all the required isolations as identified in the site specific standard isolation procedures.

Once the PTW has been prepared, the remote site operator is required to contact the Horizon Power representative by telephone, fax or email to have the PTW checked and approved by a Permit Issuer.

Prior to approving a PTW the Horizon Power representative Permit Issuer shall verify the accuracy of the proposed isolations or controls to be applied by checking the information against the current drawings, and isolation procedures for the nominated remote site.

If the Horizon Power representative Permit Issuer is of the opinion the remote site operator has identified the appropriate isolations and controls to complete the works, the Horizon Power representative Permit Issuer shall log the scope of work & date in the Permit to Work Register and issue a permit number for the remote site operator to use on the PTW form.

Note:

The remote site operator may also be required to undertake non-standard isolations by completing Sections 1 to 4 of the PTW.



9.3 Equipment Preparation – Isolate

Isolations shall be applied at a remote site in accordance with the requirements of this standard. Only an authorised Isolation Officer/HV Switching Officer can isolate the equipment.

9.4 Issuing a Remote Site Permit to Work

On completion of the isolations the remote site operator will contact the Horizon Power representative Permit Issuer to advise that all PTW isolation and/or control measures have been completed.

The Horizon Power representative Permit Issuer shall advise the remote site operator that the PTW has been approved.

On notification of approval the remote site operator shall record the name of the Permit Issuer in Section 5 of the PTW and then sign Section 6 on the PTW as the Recipient-in-Charge.

The Horizon Power representative Permit Issuer shall record the PTW details in the Permit to Work Register.

9.5 Working Under a Remote Site Permit to Work

Work may only commence under a PTW once the remote site operator has signed Sections 5 - Statement for Issue by Telephone on behalf of the Permit Issuer and Section 6 – Permit Acceptance of the PTW as the Recipient-in-Charge.

9.6 Cancelling a Permit to Work

On completion of the works, the remote site Isolation Officer/HV Switching Officer shall check that it is safe to remove all isolation and/or control measures.

Once all isolation and/or control measures are removed, the remote site Isolation Officer/HV Switching Officer shall complete Section 7 (cancellation) of the PTW and advise the Horizon Power representative Permit Issuer that the PTW has been cancelled.

The Horizon Power representative Permit Issuer shall record the cancellation in the Permit to Work Register. The PTW is now closed.

The remote site Isolation Officer/HV Switching Officer shall attach the now closed PTW to any other paperwork associated with the works along with all Isolation Tags and retain on file at the remote site for auditing purposes.

Note:

Copies of the PTW shall be retained on file at the remote site.



10 APPENDIX SECTION

10.1 Appendix A – Isolation Philosophy

Where a double block and bleed is required the vent shall be appropriately sized and

located to ensure the isolation can be adequately proven.

Note: Neither a Single block or Double Block and bleed valve(s) shall be relied upon as

an Isolation and/or Control measure for confined space entry.

Where an automated actuated valve is being used as an energy Isolation and/or

Control, the driving mechanism must be capable of being locked in the isolated position

and its motive force (e.g. electricity, air) must be capable of being positively isolated.

In the following table the box marked “E” is the equipment being isolated.

System Description Major Work

(includes any confined space entry)

Gas (e.g. gas turbine fuel supply and gas metering and conditioning)

Double block and bleed plus a spade/blind (Note 1).

Chemical Injection Points on vessels that require entry (e.g. water treatment chemicals

in storage tank)

Single block and removable spool with cap supplied for disconnected joints

Other water systems (e.g. water treatment plant)

Single leak tight closed valve + Blind (Note 1)

Nitrogen

- Heat Recovery Steam Generator required for entry to steam drum

Single block and removable spool/flexible connection

(single block and spade is acceptable for larger pipe sizes)

Compressed Air

- control valve actuators

Single leak tight closed valve

E

E

E

E

E

E



System Description Major Work

(includes any confined space entry)

CO2 and other inert atmosphere fire protection systems

- fire protection systems

Electrical and mechanical isolation as required by Horizon Power Generation isolation instructions

and procedures

Electrical As per Horizon Power Generation electrical isolation instructions and procedures

.

Note 1:

In order to limit the number of potential leak points it is acceptable to locate spectacle blinds / spades at valve/equipment flanges.



10.2 Appendix B - Permit to Work Flow Diagram

Permit to Work Flow Diagram

Re

qu

est

Pla

n &

Pre

pa

reIm

ple

me

nt

Re

vie

w &

Ve

rify

Issu

e &

Acce

pt

Ca

rryo

ut W

ork

sC

an

ce

l/C

lose

Permit IssuerIsolation officer Permit Acceptor Work PartyPermit Requestor

Define scope of work, identify equipment

and complete JRA for the workReview and validate the scope of work

Permit

required?

Work to proceed in accordance with

agreed procedures andJRANo

Review and accept scope of work, arrange

and prepare Permit requirements including

any Supplementary Permit requirements

Yes

In consultation with Permit Issuer review

scope of work and develop required

Permit Controls eg. Isolations

Implements the Permit controls (isolations etc)

and places Isolation Lock keys in Lockbox

Review and validates the Permit controls with

the Equipment Preparer and places Control

Lock on Lockbox

Articulates the Permit controls

to the Permit Acceptor

Reviews Permit conditions and controls

and acknowledges understanding of same

Dual verification of

documentation

and controls

Issues Permit to Permit Acceptor

retains copy on file for record

Accepts Permit conditions and controls and

places Personal Lock on related Lockbox

Permit conditions explained and controls

demonstrated to Work Party

Reviews and accepts Permit conditions and

controls – signs onto Permit and places

Personal Lock on associated Lockbox

Commence workMaintains Permit controls

Conditions

change

Review condition change and discuss

with Permit to Work IssuerYes

Stop Work

Complete work

Sign off Permit and

remove Personal Locks

No

Verifies the safety of Work Party, ensures the site

is safe and relinquishes control of the Permit

Validates the completion of

work and cancels the Permit

Removes the Permit controls

as requiredPermit Closed

Do the changes

introduce a hazard

not controlled in the

Permit?

Yes

Verifies the safety of Work Party,

Personal Locks removed and

relinquishes control of the Permit

NO

Yes



10.3 Appendix C – Associated GPTWS links

The following section outlines the links for all related documents:

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/1893654 - Permit-to-Work permit

register

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10186760 - Permit-to-Work permit

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10189422 - Sanction-to-Test permit

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10189888 - Excavation and

trenching permit

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10196628 - High Voltage (HV)

Electrical Access permit

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10191030 - Emergency Lock

Removal form

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10191043 - Generation Permit-to-

Work Standard (GPTWS) Operating Agreement

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/10191701 - High Voltage (HV)

Switching Schedule form

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/3227438 - Confined-Space Entry

Permit

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/3230109 - Hot Work Permit

http://dm.horizonpower.com.au/otcs/llisapi.dll/open/1893654










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