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Working safely around the Western Power network
Published 2015
@westernpowerwa /westernpowerwa /western-power /westernpowerwa
Western PowerEmergencies and power outage .................................................. 13 13 51 (24 hours, seven days a week)
General enquiries .............................................................................13 10 87 (7am - 5pm Monday to Friday)
Telephone interpreter services: 13 14 50 TTY users (speech or hearing impaired only): 1800 13 13 51 Fax: (08) 9225 2660 Email: [email protected] Web: westernpower.com.au
363 Wellington Street Perth WA 6000 GPO Box L921 Perth WA 6842
This information is available in alternative formats if requested.
FREE information sessions and presentations • Sessions conducted in your workplace and tailored to your business needs.
• Topics covered include: danger zones, working safely around overhead and underground network assets, clearances, permits, authorisations, due diligence, duty of care, planning.
Contact: [email protected] or General Enquiries on 13 10 87
Emergency service .............................................................................000
Dial Before You Dig Freecall ..........................................................................................................1100Web: 1100.com.au
Disclaimer
This document contains general information only. Western Power shall not be liable for any loss or damages arising from
the use of the information contained in this document. Users of this document are responsible for determining the
currency, relevance and applicability of the information contained in this document to their particular circumstances.
Western Power recommends users of this document obtain independent advice before seeking to rely on any information
set out in this document.
Directory
About Western Power 2
Keeping safe around the Western Power network 8
• Reporting electrical incidents and emergencies 10
• Buying property or planning to build near the network 12
• Working near the network 16
• Overhead network safety 17
• Underground network safety 19
• Oversize vehicles 24
• Rural safety 26
• Recreational and agricultural aerial safety 28
Electrical safety around homes 30
• Private power poles, powerlines and underground cables 32
• Electrical assets around homes 34
• Seasonal safety 36
Additional information 38
1
Public safety
Working near powerlines and other electrical infrastructure can be extremely dangerous and can cause serious injury or death. Public safety is a shared responsibility for Western Power and for the people who need to work near our network.
Contents
2 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
About Western Power
Western Power is a State Government-owned corporation that builds, maintains and operates the electricity network in the south west corner of Western Australia.
........................................
......
......
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KALBARRI
GERALDTON
PERTH
KALGOORLIE
BUNBURY
ALBANY
Our purpose is connecting people with electricity in a way that is safe, reliable and affordable. We have over one million connected customers including homes, businesses, factories, mines, schools and hospitals across the south west of Western Australia.
We do not generate electricity and/or retail electricity (like Synergy for example) or operate in other parts of Western Australia, which is covered by Horizon Power and other private network operators.
An isolated and self-contained network, the Western Power network covers a very
large area of 255,064 square kilometres.
The Western Power network
3
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Circuit length (kilometres)
Transmission
Total
100,302.9kilometres
Overhead
7,731.7 Underground
70.5Total
7,802.2
Distribution
Overhead
68,331.5Underground
24,169.2Total
92,500.7
Poles and towers
Transmission DistributionTotal
811,77341,238 770,535
Transmission substations
Terminal substations Zone substations Total
substations
155
Streetlights
252,702
26
129
Combined transformer capacity
Total capacity bulk
(terminal) power
transformers
7,292 MVA1
Total capacity
sub-transmission
(zone) power
transformers
8,407 MVA
Number of
distribution
transformers
67,554
Total capacity
distribution
transformers
9,577 MVA
Network metric
1 MVA = Megavolt ampere
Information current as at 30 June 2015.
5
GENERATION
OUR CUSTOMERS WESTERN POWER OUR CUSTOMERS
TRANSMISSION & DISTRIBUTION RETAIL
Supply chain
Generators make electricity at power plants using a variety of fuel sources.
The network or grid consists of transmission and distribution assets.
Retailers manage the interface between the network and consumer.
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Distribution polesThe distribution network is used to transport electricity from zone substations to individual customers. The voltages range from 415V to 33kV. Other distribution assets include transformers, pillars, overhead and underground cables.
There are many different types of transmission and distribution assets in use today, depending upon the location, environment and stage in the asset’s lifecycle. Here are some typical examples of overhead assets.
Transmission poles and towersThe transmission network transports electricity from large generators to transmission terminal stations and zone substations. The voltages range from 66kV to 330kV.
Western Power network assets
7
Keeping safe around the Western Power networkElectricity by nature is hazardous
8 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
9
Staying safe around the Western Power network is a shared responsibilityElectricity is, by its very nature, hazardous.
Western Power is committed to reducing the risk posed to the public from network assets and creating greater awareness about working safely around our network.
Safety is a shared responsibility for us and for anyone planning work or working around the Western Power network.
Safety around the Western Power networkThis document provides information and advice on how you can keep safe when you are working near Western Power’s electricity network or around the home.
It has been developed for use in conjunction with the standards and regulations applicable to your industry and to allow you and your business to put adequate risk management procedures in place before working around the Western Power network.
State and Federal legislation, industry standards, codes of practice and guidelines provide the minimum requirements to safely undertake work applicable to your industry. However, it is your behaviour that is the last barrier between you and an incident. It is your duty of care to provide a safe workplace, to manage risk so far as is reasonably practicable and to protect against hazards. If you are unclear about your obligations we encourage you to seek guidance from guidelines specific to your industry. (OSH Act 1984 – section 19).
Duty of careWestern Power is focused on delivering a safe supply of electricity to each and every customer within our network.
We are obligated to maintain our infrastructure and in cases of damage, to repair that infrastructure promptly to ensure the safety of the network.
This is our duty of care. A duty of care is also owed to the network operator by anyone working near it. If it is reasonably foreseeable that your works may impact upon overhead and/or underground assets then you must demonstrate due diligence as it applies to duty of care. Have you taken reasonable steps to avoid causing damage? Examples can include, but are not limited to:
Your actions are the last barrier between you and an incident.
6.
1. Seeking out asset information well in advance from Dial Before You Dig and/or Western Power.
2. Performing an onsite inspection to ascertain the existence, location, depth and alignment of assets.
Observing safe approach distances as stipulated by OSH Regulations section 3.64 and any other relevant industry standards and requirements.
4. Performing a job risk assessment and developing a safe work method statement to manage the risk.
3. Considering options that do not require working near the Western Power network.
5. Proving the location of assets using safe methods as advised by Dial Before You Dig.
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Reporting electrical incidents and emergencies
Report all electrical incidentsYou must report all incidents of electric shock and accidents, no matter how minor they are, to Western Power and your employer if it occurs at your place of work.
This is a requirement of the Electricity (Licensing) Regulations 1991.
An electric shock is an incident which does not require medical or first aid treatment. If you receive an electric shock we recommend that you have a medical assessment as a precaution.
An electrical accident is an incident which requires medical or first aid treatment and includes fatalities.
Reporting emergenciesAn emergency can be:
• tingling or slight shocks received from taps and/or appliances
• fallen, broken or arcing powerlines
• clashing conductors
• dangerous poles, which are leaning or sparking
• a fire on or near the Western Power network
• a pole that has been hit by a vehicle or lying on the ground
• underground cable, green dome or kiosk damaged or exposed wires
• substation door open.
Accidents near the Western Power networkIf you see a fallen powerline or pole, always assume that it is live. Do not go near it, touch it or anything that is in contact with it.
Electricity from powerlines can jump or ‘arc’ through the air and travel to earth through your body, resulting in an electric shock. In the event of an electrical accident involving powerlines:
• in a life threatening emergency, call emergency services on 000
• phone Western Power on 13 13 51 to report a fallen powerline and to make the area safe
• do not go near an injured person if it means going near powerlines
• stand back and urge other bystanders to keep at least 6m away
• do not approach the area until the proper authorities have declared the area safe.
In addition to the fallen powerlines, there may also be damage to support structures and equipment. It may not be easy to see damage to structures, so always keep a safe distance.
Accidents in the homeTo avoid electrical incidents within the home, have a licensed electrician regularly check the condition of your electrical wiring and consumer electrical installations connected to the home.
If an electrical accident occurs in the home:
• in a life threatening emergency, call emergency services on 000
• do not go near the injured person if they are still in contact with the electrical current
• if the area is safe, check the victim for a response, breathing and pulse. If necessary start resuscitation. Do not touch burns, break blisters or remove burned clothing. Always seek medical advice after an electric shock, even if injury is not apparent
• if the incident has happened in the home, report it to Western Power on 13 13 51, and contact a licensed electrician to check the wiring and consumer electrical installations connected to the home.
How to report an emergencyIf you see an emergency involving Western Power assets:
1. Call emergency services on 000.
2. Call Western Power on 13 13 51.
3. Keep bystanders clear – at least 6m from any impacted network assets.
4. Wait for Western Power to attend to make the area safe.
11
Vehicles and powerlinesIn the event that your vehicle is in contact with a power pole and brings down the powerline it is safest to remain in the vehicle and wait for emergency services to arrive. As a guide:
• turn the vehicle off to cut off the fuel supply
• call emergency services on 000 (emergency services will contact Western Power to make the area safe)
• if possible remain in the vehicle until the power has been isolated and earthed.
An emergency evacuation of a vehicle is extremely dangerous. If you need to evacuate your vehicle because of a fire:
• jump clear of the vehicle and make sure you land with your feet together. Do not touch the vehicle and the ground at the same time as this may create a path for the electricity to flow to earth through your body, resulting in electrocution
• calmly move at least 6m away from the vehicle using short shuffle steps
• do not return to the vehicle until the authorities have declared the area safe
• stand back and urge other bystanders to keep at least 6m away.
Evacuating a vehicle
If you see an emergency, call Western Power on 13 13 51.
12 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Buying property or planning to build near the network
Before purchasing a property or planning any land improvement, it is important to consider the location of existing and proposed electrical infrastructure:
• consider local building codes and planning requirements that may have an impact on the land you can use
• identify easements on the property’s Certificate of Title and any associated conditions which may restrict land use or access
• consider the restriction zone associated with electrical infrastructure. An easement may not be registered on the property, however the restriction zone will still impact land use.
To find out more about Western Power’s planned works in your area, refer to Western Power’s website and our Annual Planning Report at westernpower.com.au
For Local and Regional Structure plans for you area, refer to the Department of Planning at planning.wa.gov.au and your Local Government Authority.
Before you start any work on private property, you may need development application approval and building permits from your Local Government Authority. This includes but is not limited to:
• building and erecting permanent and temporary structures
• changing land use
• building improvements (for example installing a pool, renovations)
• installing fences or walls.
Requesting information about the Western Power networkFor information about overhead and underground Western Power network assets in your work location contact Dial Before You Dig on 1100.com.au or free call 1100. Dial Before You Dig is a free national referral service supported by Western Power.
EasementsOur electricity network covers more than 255,000 square kilometres. This means that powerlines and structures are frequently located on or near private property, particularly in rural and remote areas.
In some areas Western Power may have an easement registered on the Certificate of Title of a property. An easement, sometimes referred to as a ‘wayleave’, provides a ‘right of way’, allowing Western Power and its contractors to access land to build and maintain electrical infrastructure on private property.
If you have an easement registered on your property, there may be some restrictions on the activities performed or structures that can be placed within the easements.
Some examples of easement conditions include restrictions on:
• building houses or other structures
• excavating or changing the ground level
• erecting fences higher than 2m
• stockpiling or storing any materials or garbage
• planting or cultivating trees or shrubs that impinge on clearance zones
• installing and using irrigation equipment
• burning off.
Restriction zone In the absence of a registered easement, a restriction zone applies to the area adjacent to a powerline within which clearance restrictions must be observed. The restriction zone is a distance defined by the line voltage, current rating, distance between poles, pole height and deflection and is calculated on a case by case basis in line with the Australian Standard for overhead line design (AS/NZS 7000:2010).
Western Power can provide standard easement conditions on request. These conditions detail the works or developments that are subject to constraint within an established easement or restriction zone.
In general, Western Power does not support any development within the restriction zone of an overhead powerline unless it is properly assessed and approved by Western Power in accordance with relevant standards and procedures.
Check the Certificate of Title for any easement conditions relating to the property.
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Safe clearance to the overhead networkAll new developments are subject to the requirements of the WA Electrical Requirements 2014 and AS/NZS 7000:2010 Overhead line design.
Western Power or a suitably qualified and competent professional can assist you to calculate the restriction zone on request. Western Power completes the engineering assessment which includes a survey component and you can arrange for the survey through a licensed surveyor.
Easement and restriction zones
RESTRICTION ZONEEasement
PR
OP
ER
TY
BO
UN
DA
RY
ROAD RESERVEEASEMENT
PR
OP
ER
TY
BO
UN
DA
RY
RESTRICTION ZONE
MINIMUM BUILDING SETBACK
No easement
ROAD RESERVE
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Building setbackBuilding setbacks specify the minimum distance that structures can be placed from the property boundary and are determined by your Local Government Authority. Minimal or zero setbacks when developing a property may not be achievable where there is a powerline adjacent to the property. Prior to establishing any plans, it is highly advisable that you refer to the Residential Design Codes of Western Australia or contact Western Power for advice.
If a development cannot proceed due to proximity of a powerline, there are two possible courses of action:
1. Amend the plans for the development to maintain adequate clearance and/or
2. Reconfigure or relocate the powerline.
Difficulties may occur if the presence of the powerline is not taken into consideration early in the planning process. If work configuration or relocation of a powerline is required, contact Western Power for more details.
Swimming poolsWhen planning to install a pool, make sure that the overhead service cables connecting your property will not go across the pool. A licensed electrical contractor can relocate the private consumer pole or redirect the point of attachment a safe distance away from the swimming pool. Refer to the WA Electrical Requirements (2014) for further information on the required clearance distances for low voltage overhead and underground service connections.
Relocating assetsWestern Power’s network assets can be relocated, reconfigured, raised or placed underground however, depending on the requirements, network configuration and local area, the cost of relocating or moving can be significant and lengthy. The cost to underground an overhead powerline can be significantly greater than the relocation of an overhead asset.
The person requesting the relocation is responsible for all related costs and may be required to obtain the necessary stakeholder approvals associated with the relocation or removal of the Western Power asset.
You can apply to relocate Western Power assets by completing a relocation form available on our website. There are different types of asset relocation requests:
• general asset relocations can involve a range of work, from the movement of green dome, a pole to pillar request or the relocation of a section of underground cable or overhead powerline
• reconfiguration occurs where the arrangement at the top of a pole is changed to perhaps minimise the easement of an adjacent property, or to improve the separation between the line and an existing or proposed building. Reconfiguration work may also require poles to be changed.
In some circumstances the relocation of assets may not be feasible, and in others the electricity supply to the property may be temporarily interrupted to allow for works to be undertaken.
To apply to have assets relocated visit westernpower.com.au, email [email protected], or contact us on 13 10 87.
Network assets can be relocated, reconfigured, raised and undergrounded. Cost and time implications apply for the application.
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The process for working near electricity
Our requirements
You intend to work near the Western Power network and want to complete the work safely.
To do this you, your employee/s or someone you engage is deemed to be a qualified and competent person who can:
• demonstrate knowledge and practical application of relevant codes of practice and industry standards
• conduct job risk assessments and develop and implement safe work method statements relevant to the work
• provide advice on how to complete the work safely in consideration of the work site environment and to document this to the satisfaction of Western Power and any other relevant organisation
• meet other obligations required by legislation.
Step 1 Contact Dial Before You Dig on 1100.com.au or free call 1100 to determine the location and voltage of Western Power overhead and underground network assets.
Step 2 When you have received the information you requested, conduct a job risk assessment and develop safe work method statements relevant to the work.
Step 3 If you cannot work outside the danger zone, request the appropriate option from Western Power for your proposed works.
Your options Based on your request and at your expense, Western Power may:
• install aerial visual covers on low voltage overhead lines (tiger tails)
• isolate the low voltage network
• isolate the high voltage network
• relocate Western Power assets.
Or you may choose not to proceed with the work.
Always assume powerlines are live. If you see a fallen powerline, make the safe call to Western Power on 13 13 51.
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Working near the network
Working near powerlines and other electrical infrastructure can be extremely dangerous and can cause serious injury or death. The information in this book has been developed for use in conjunction with the standards and regulations applicable to your industry and to allow you and your business to put adequate risk management procedures in place before working around electrical assets.
It is essential to know the location and voltage of any underground power cables and overhead network assets in the vicinity of your work area to assess the risk and carry out work safely.
Dial Before You Dig is a free national referral service supported by Western Power and is the most efficient way to obtain information on underground and overhead services near your work site. Visit 1100.com.au to lodge an enquiry or freecall 1100.
To protect yourself and others against injury, it is your responsibility to:
• locate and keep clear of Western Power assets near your work area
• complete a detailed job risk assessment of the work area. Make sure everyone working in the area understands the risks and how they will be managed
• we strongly recommend that you also engage a qualified service provider to assist you to identify and manage any risk before you start
• consider the height and size of any machinery that you intend to bring on site. Always use the right tool for the job
• when delivering material to site, ensure that an appropriate lay down area has been set up away from the network
• use a safety observer to monitor and warn against unsafe approach to live equipment or other unsafe conditions. The observer must be competent and have the authority to stop the work if necessary.
Your duty of careA person (or company) has a duty to all other persons to take reasonable care in relation to ‘foreseeable risks’ of harm. Reasonable care means you avoid any acts or omissions which you can reasonably foresee would be likely to injure someone.
What do we mean by the Western Power network?Western Power’s electricity network includes overhead and underground cables, power poles and streetlights, switchgear enclosures (ring main unit), pillars (green domes), transformers, and substation buildings.
Do not touch or interfere with any part of the electricity network. Only authorised Western Power employees or contractors are permitted to access or work on Western Power assets.
Always assume powerlines are live. If you see a fallen powerline phone Western Power on 13 13 51 to report it and to make the area safe.
Do not touch anything that is in contact with powerlines, for example tree branches. If you touch a tree that is in contact with a powerline, you risk serious injury or death from electric shock.
17
Overhead network safety
Working near the Western Power network is dangerous. If you are in charge of the work area you must make sure that no person, plant or material enters the danger zone of an overhead powerline or other electrical network assets.
It is your responsibility to make sure that the proposed work can be performed safely outside of the danger zone.
The defined danger zone should be applied in conjunction with the standards and regulations applicable to your industry.
The more onerous requirements should apply.
Danger zones around overhead powerlines
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Danger zoneA danger zone is a specific area surrounding live electrical apparatus that ordinary persons, equipment and materials must not enter. The size of the danger zone is determined by the voltage of the electrical apparatus.
If your works enter the danger zone as prescribed in section 3.64 of the Occupational Safety and Health Regulations 1996, or you make contact with the network, you may be prosecuted and be liable for any damage to the network.
Always:
• look up, look down and look around and familiarise yourself with the location of network assets
• check the height of loads
• determine the extension, reach and height of equipment.
Where possible:
• do not lift loads directly underneath powerlines
• do not lift loads over powerlines
• establish your lay down area or site storage away from the Western Power network
• place waste bins outside of the danger zone
• tip sand outside of the danger zone.
Work within the danger zone If you have completed a detailed job risk assessment and safe work method statement and determined that you are unable to work outside of the danger zone, in some circumstances you can apply for permission to work within the danger zone. This may require appropriate supervision by a person accredited by Western Power and additional controls such as mechanical barriers or other site specific controls.
Alternatively we can de-energise and isolate the electricity network.
Consider the following for works inside the danger zone:
1. you must contact Western Power at least six weeks in advance if you are unable to work outside of the danger zone
2. if Western Power has planned maintenance or seasonal constraints, your work may not be authorised to go ahead
3. if a permit to work has been issued, it may be cancelled at short notice depending on network constraints
4. Western Power must complete an engineering assessment. The assessment includes a survey component which you can arrange through a surveyor.
John is a crane operator and plans to install a pool at a residential property. John has completed a site assessment and Dial Before You Dig enquiry and has identified an overhead powerline next to the property.
The Dial Before You Dig plans identify that the powerline is low voltage (less than 1000 volts). After referencing the OSH Reg 3.64 John determines that the required danger zone is 1m.
To put the pool into its final position it must be lifted above the powerlines. The Australian Standards for Cranes, hoists and winches – Safe Use (AS 2550.1:2011) illustrates that loads cannot be lifted over powerlines without notifying the network provider. John contacts Western Power and provides a copy of his safe work method statement (including the use of a spotter, visual and mechanical barriers, tiger tails and securing the load) and job risk assessment to
demonstrate that he is able to safely work outside of the danger zone and above the powerlines so far as reasonably practicable.
The following day, John arrives at the property and implements his safe work method statement and controls to manage the risk and safely complete his work.
Case Study – Overhead network safety
19
Underground network safety
Excavating can be dangerous if you do not know what is below the surface. If you are supervising the work area you must make sure that everyone on site is aware of the location of Western Power assets and the controls to prevent contact with the network.
When working near underground assets, it is your responsibility to ensure that the proposed work can be carried out safely.
Works may include but is not limited to:
• excavating/trenching
• earthworks
• landscaping (e.g. reticulation)
• potholing
• directional drilling
• installing fencing, post, signage, street signs.
Planning and preparationDial Before You Dig can help prevent damage and disruption to underground pipe and cable networks, including electricity, gas, communications and water. Contact with a single cable or pipe can leave an entire community without essential services and may
result in injury or death. There are also heavy financial penalties for negligent behaviour and you may be liable for damages or injuries.
Western Power can provide additional asset information (e.g. voltage and the location of customer owned assets) to assist you in determining the minimum approach distances for safe excavation.
Dial Before You Dig plans will only show the Western Power network. The underground service cable from a green dome is owned and maintained by the property owner and will not be shown on the Dial Before You Dig plans. As the path of the underground service cable to the property is not mapped, caution must be applied when undertaking any works in the vicinity.
Identify the location of underground assetsThe location and depth of cables shown on the Dial Before You Dig Plans are a guide only. Services may not be located in the area shown on the plans.
Verify the location of underground services using a non-destructive underground service location methodology. Western Power recommends you use an accredited underground service locating
contractor. Do not use mechanical excavators to expose underground services or to prove the location of assets.
Once services shown on the Dial Before You Dig plans have been identified, the location should be proven and visually identified by potholing. Additional potholing should also be undertaken in the work area to identify services that may not be shown on the Dial Before You Dig plans.
Underground service locating contractors are not permitted to interfere with the Western Power network. This includes accessing Western Power assets to affix cable locating equipment.
We do not endorse the use of prodders or similar tools to prove the location of cables. Contact with the network can result in latent damage to the cable insulation and place others at risk.
If a Western Power cable shown on the Dial Before You Dig plans cannot be found after service locating and potholing and you do not believe it is safe to proceed, stop stop work and call 1300 769 345 during business hours, or in an emergency make the safe call to Western Power on 13 13 51.
20 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Different coloured conduit can be used to identify underground services. Underground power cables are often installed in orange or black PVC conduit, but never assume that another coloured conduit does not contain electricity cables. In some areas, electrical danger tape or a mechanical barrier such as a hard PVC cover, sand/cement mix, and/or concrete cement, may be installed above the cables. Under no circumstance should you attempt to cut or remove the hard cover or danger tape.
Communications cables are generally encased in a white PVC conduit.
The Utility Providers Code of Practice provides an indicative alignment of underground services. This code of practice should be used as a guide only as services may not be installed on the right alignment.
ProtectInstall safety barricades and traffic management around the excavation site to ensure the safety of the public and work crew.
Reinforce the area surrounding the exposed services to ensure that Western Power assets are not damaged.
ProceedOnly commence digging once you have identified and proved the location of underground services.
Only commence digging once you have identified and proved the location of underground services.
The location of private underground service cables are not shown on Dial Before You Dig plans.
21
Joe works for a small excavation business and has been tasked with installing an underground pipe in the road reserve. As a part of his job risk assessment ,Joe submits an online Dial Before You Dig enquiry at 1100.com.au to determine the location and voltage of all overhead and underground services in his work area. John is issued with maps detailing the location of a low voltage (<1kV) overhead powerline and high voltage (1kV – 33kV) underground cable in his work area. Based on the Dial Before You Dig information, Joe
confirms that his machinery will need to be operated in close proximity to the underground cable and overhead powerline. Joe then prepares a job risk assessment and determines that he can work safely outside the danger zone of the overhead powerline.
Joe organises for the underground cables to be located by a service locator, and marks the indicative location with paint as a part of his job risk assessment. A qualified safety observer is also present on the site at all times when the works are undertaken to ensure that the excavation proceeds with care.
Based on the recommended approach distance to the underground cable (50 centimetres in this instance), Joe potholes by hand to prove the location of the assets. Joe then proceeds to protect the asset by installing safety barriers and reinforcing the area. Now that the asset has been proved by careful hand digging and protected, Joe knows that he can proceed with care.
Case Study – Underground network safety
Minimum approach distances for underground cables
Nominal voltage
Minimum approach distance
Power tool or plant
Non-powered hand tool/non-destructive digging
Up to and including 1,000V 30cm
Approach with care, avoid contact
1,000V up to and including 33kV 50cm
Greater than 33kV up to and including 132kV
3m*
* Western Power must assess any works within 3m of cables 33kV and above. Permit and/or authorisations for your works may be required.
Non-destructive digging (or potholing) is the use of high pressure compressed air to break up the ground, which is then removed by a powerful vacuum unit.
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Guidelines for undertaking excavation work1. Contact Dial Before You Dig to obtain a cable location plan –
visit 1100.com.au or free call 1100. Plans supplied include overhead powerline and underground cable voltage information which is used to determine minimum approach distances.
2. Follow the 4 Ps process: Plan, Pothole, Protect and Proceed. For further guidance on safe work practices relevant to your industry contact Worksafe WA or your industry association.
3. Determine if the proposed excavation is within the minimum approach distance of any underground cables and/or overhead powerlines using your industry standards, codes of practice and guidelines regarding safe excavation.
4. Consider the operating height and reach of any excavation equipment to ensure that it does not enter the danger zone for overhead powerlines.
5. Engage a qualified underground service locating professional to confirm the locations of known and any unknown underground services in the work area.
6. Determine the collapsible area of the proposed excavation.
7. Determine if any part of the underground and/or overhead electrical assets will be inside the collapsible area of the proposed excavation (including buildings, walls and fences) and implement any requirements to shore the trench.
8. Pothole by hand or other non-destructive means to remove small amounts of soil to prove the location and depth of underground services. Check that no services have been exposed after each shovel load.
9. Only use mechanical excavation after all services have been identified and exposed.
10. Proceed with care.
11. Stop work and call Western Power on 13 10 87 if you are unable to locate an underground cable, encounter any issues associated with the underground network such as damaged insulation or cables or in the event that you discover a cable not shown on your plan.
Further guidance on safe excavation in WA is provided in WorkSafe’s Excavation Work Code of Practice 2013.
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Preventing ground collapseGround collapse is one of the primary risks to be controlled in excavation work. Ground collapse can occur quickly and without warning, giving a worker virtually no time to escape. When planning the work, select appropriate excavation methods and control measures for the working environment and consider the collapsible areas for overhead and underground assets.
Examples of typical underground and overhead network assets which can be at risk of collapse into an excavated area are depicted below.
UNDERGROUNDPOWERLINES & PILLARS
GROUND MOUNTEDTRANSFORMERS
UNDERGROUNDPOWERLINES
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
UNDERGROUNDPOWERLINES & PILLARS
GROUND MOUNTEDTRANSFORMERS
UNDERGROUNDPOWERLINES
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
UNDERGROUNDPOWERLINES & PILLARS
GROUND MOUNTEDTRANSFORMERS
UNDERGROUNDPOWERLINES
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
Collapsible areas for underground assets
UNDERGROUND CABLES
UNDERGROUND CABLES & PILLARS
GROUND MOUNTED TRANSFORMERS
STREET LIGHTCOLUMNS
POWER POLES SUPPORTING STAY WIRES
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
UNDERGROUNDPOWERLINES & PILLARS
GROUND MOUNTEDTRANSFORMERS
UNDERGROUNDPOWERLINES
STREET LIGHTCOLUMNS
POWER POLES SUPPORTING STAY WIRES
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
UNDERGROUNDPOWERLINES & PILLARS
GROUND MOUNTEDTRANSFORMERS
UNDERGROUNDPOWERLINES
STREET LIGHTCOLUMNS
POWER POLES SUPPORTING STAY WIRES
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
EXCAVATIONAREA
COLLAPSIBLEZONE
UNDERGROUNDPOWERLINES & PILLARS
GROUND MOUNTEDTRANSFORMERS
UNDERGROUNDPOWERLINES
Collapsible areas for overhead assets
POWER POLES SUPPORTING STAY WIRES
STREET LIGHT COLUMNS
Further guidance on safe excavation in WA is provided in WorkSafe’s Excavation Work Code of Practice 2013.
24 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Transporting oversize loads can be dangerous, especially if steps are not taken to ensure the load remains a safe distance from powerlines.Main Roads WA requires Western Power to authorise all load movements around the State where the load is more than 4.3m high (4.6m for livestock vehicles and towed agricultural machinery). Transport operators must refer to Main Roads WA before applying to Western Power for authorisation.
Authorisation to transport oversized loadsOnce we receive your application we will assess if the load can travel safely and what special conditions, if any, are required. We will then issue an Oversize Load Movement Authorisation setting out the conditions which must be adhered to at all times.
In some cases substantial planning and/or construction works are required (e.g. undergrounding, moving or raising powerlines). In these cases Western Power will quote on the work required.
Load movements within Western Power and Horizon Power networks (inter-district)If you need to transport oversize loads between Western Power’s network and Horizon Power’s network, you can lodge a single inter-district application for travel with the network at the point of origin.
Oversize vehicles
High wide load corridors are managed by Main Roads WA.
Case Study – Oversize vehicle movementTracey works for a small company that provides heavy haulage mining equipment and needs to arrange a delivery of earth equipment to site. The equipment is 5m high.
Tracey contacts Main Roads WA with her route plan to get a permit for travel. As the height of the load is over 4.3m, Main Roads WA directs Tracy to seek authorisation from Western Power. Loads over 4.3m high will often be very close to powerlines.
Western Power assesses Tracey’s application and determines that an escort is required to ensure that the
vehicle is kept clear of powerlines at all times.
As such the network operator makes contact with Tracey to discuss the implications. Tracey and Western Power come to terms on their approach to the job. An Oversized Load Movement Authorisation is issued. Tracey understands that once the authorisation is issued no changes can be made. If changes are required a new authorisation must be issued, incurring a new permit processing fee.
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Oversized vehicle incident.
Refer to Main Roads WA before applying for an Oversized Load Movement Authorisation – mainroads.wa.gov.au
26 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Rural safety
If you are working on a farm you need to be aware of the electrical hazards around you.
Stubble burning Stubble burning requires careful planning and constant monitoring as it can cause widespread damage and power interruptions if it gets out of control. Things to consider include:
• check for overhead powerlines before starting work
• clear vegetation from around the base of power poles to at least 1.5m
• dampen the base of poles before and after stubble burning
• do not rake wind rows beneath or next to powerlines or poles
• have mobile fire units that are easily accessible should a stubble fire get out of control.
Follow general advice for all prescribed burns: inform your local government fire control officer and neighbours prior to commencing, stay up to date with the latest weather information, check the fire danger rating for the area and whether any bans are in place, do not go ahead if conditions are hot, dry or windy or forecast to become so and do not take unnecessary risks.
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Harvesting and seedingHarvesters and seeders are at high risk of coming into contact with powerlines. You can reduce this risk by following these steps:
• check for overhead powerlines and poles before starting work
• know the height and width of your machinery and have this information displayed
• if you haven’t worked in a paddock for a while, check for any new infrastructure or electrical hazards
• do not assume the height of overhead powerlines as the clearance may change throughout the day due to sag in hot weather or periods of increased power demand
• do not harvest or seed when weather conditions are not suitable. Check the Department of Fire and Emergency Services, Department of Parks and Wildlife and local government fire warnings and heed their advice. Note that fire warnings may differ between agencies and vehicle movement bans may change during the day
• crops such as swathed canola coming into contact with powerlines may lead to a power interruption. Sometimes the obstruction may clear itself but if not, under no circumstances attempt to remove the obstruction. Report the incident to Western Power on 13 13 51
• if machinery does make contact with powerlines, stay in the cab and phone Western Power for assistance on 13 13 51. Do not attempt to exit the vehicle until Western Power has determined that it is safe to do so.
Accessing private propertyWestern Power is responsible for maintaining the safety of its network, and we sometimes need access to properties to inspect and maintain our assets. We will make every effort to contact you before starting any planned inspection or maintenance activity. This includes the inspection and maintenance of some vegetation near the network.
To minimise disruption to you, our Poles in Paddock Network Maintenance Program lets you register your details with us so we can contact you before accessing your land.
Go to westernpower.com.au and search for ‘poles in paddock’ to register.
Western Power accesses property to maintain the safety of the network.
28 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Recreational and agricultural aerial safety
Flying near powerlines is extremely dangerous and Western Power recommends that you do not fly under powerlines. Powerlines pose a significant risk to low flying aircraft because they can be difficult to distinguish from the landscape, even in clear conditions.
Assume that powerlines are present in rural, semi rural and populated areas. Keep in mind that they also exist in remote areas where you may not expect them. Although they often provide a convenient corridor, powerlines do not necessarily follow roads. Lines of cleared vegetation or firebreaks can also be a good indicator that powerlines are present. Powerlines may also cross bodies of water such as rivers and lakes.
Trees and other vegetation can obscure the view of powerlines and poles and irregular terrain can make them difficult to spot from the air. Even when spotted, the distance of a powerline from the aircraft may be hard to calculate due to lack of reference points or distorted by optical illusion. Some powerlines in areas with high levels of aerial activity may have markers to improve the visibility of the powerline, but this is not always the case.
Powerlines are also built in many configurations and the height and ground clearance of powerlines will vary in different locations. The height of powerlines from the ground can also vary due to sag in hot conditions or in periods of increased power demand and may not offer the same clearance as previously measured in all weather.
We recommend that before flying you:
• plan ahead and familiarise yourself with the location of powerlines and other obstacles such as telecommunications towers and poles in the area
• always undertake a new job risk assessment of the area each time you fly as new infrastructure may have been added or moved
• refer to the Civil Aviation Safety Authority website at casa.gov.au for more information.
Typical low level flying activities include, but are not limited to:
• aerial application (crop dusting)
• mustering
• recreational activities
• powered aircraft (including drones, and remote control devices)
• kite flying/surfing
• hot air ballooning, glider, hand gliders and paragliders.
If contact with powerlines occurs:
• turn the aircraft off to cut off the fuel supply
• call emergency services on 000 from a landline or 112 from a mobile phone (contact your provider for details about your service)
• never touch overhead or fallen powerlines or anything in contact with them
• phone Western Power on 13 13 51 to report the incident and to make the area safe
• if you are in a grounded aircraft or vehicle, and it is safe to do so, stay inside the cabin. Do not leave the cabin until the power is switched off and you have been given the all clear by Western Power
• stand back and urge other bystanders to keep at least 6m away.
The Civil Aviation Safety Authority is responsible for providing safety regulations, education and training for air operations in Australia and requires pilots to undertake special training and endorsements to be able to legally conduct low level flying.
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Electrical safety aroundhomes
It is your responsibility to ensure that private power poles and powerlines are safe.
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32 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
It is your responsibility to make sure that private power poles, powerlines and underground cables are safe.
If we identify an unsafe connection with your electrical equipment where it connects to the Western Power network, we may need to disconnect the power supply until it is fixed by a licensed electrician.
We will give you information about the issue and the steps needed to restore the electricity supply.
Private power poles and powerlinesA fallen power pole or powerline has the potential to result in a ground fire or electric shock.
If you have private powerlines or a private power pole on your property, it is your responsibility to inspect and maintain them. If you are unsure where Western Power’s network ends and where your responsibilities begin, call us on 13 10 87.
As power poles and powerlines are routinely exposed to inclement weather conditions and pests, they are susceptible to structural damage. Damaged or degraded power poles and powerlines can lead to fires and/or electric shock so it is important that you maintain them.
Have a qualified, licensed professional regularly inspect the condition of private power poles and powerlines as underlying structural issues or internal deteriorations may not be visible to the naked eye.
The diagram overleaf is an example of common private powerline arrangement. Further information about ownership of private power poles, powerlines and underground cables is available from EnergySafety.
Private power poles, powerlines and underground cables
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The diagram shows the separation between network assets and privately owned assets. Further information about ownership of private power poles, powerlines and underground cables is available from EnergySafety.
Private power pole and network operator’s service cable
MAINSWITCHBOARD /
METER BOX
PRIVATEPOWER POLE
NETWORK OPERATOR’SPOWERLINES
NETWORK OPERATOR’SSERVICE CABLE
PROPERTYBOUNDARY
NETWORK OPERATOR’SSERVICE CABLE
34 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
It is important to know where your meter box is in case of emergency.Your meter box houses a number of electrical components including the meter, main switch, fuses and circuit breakers, which control the flow of electricity into your home.
For your safety:• ask a licensed electrician to inspect
your meter box if it shows any signsof burn marks, worn wires or astrange smell
• switch the power off at the mainswitch if you are doing anyhousehold maintenance orrenovations
• label all switches, circuit breakersand fuses in the meter box for easyidentification
• keep trees and shrubs away fromyour meter box
• install circuit breakers or a safetyswitch. Safety switches aremandatory in all new homes. Theycan save lives and prevent injuryfrom electric shock
• check your safety switch every sixmonths or in accordance with themanufacturer’s instructions
• check circuit breakers every twoyears or in accordance with themanufacturer’s instructions
• if a fuse, safety switch or applianceblows repeatedly have a licensedelectrician check it
• have fuses replaced by a licensedelectrician
• make sure that the meter box isprotected from exposure to theelements and has a meter box lid.
Safety Switches
Safety switches provide an important defence against electric shock and are mandatory in all new homes. A licensed electrician should install all safety switches except portable units.
A safety switch is designed to immediately switch the power off when harmful levels of electricity (usually 30 milliamps) ‘leak’ to earth. Safety switches typically operate within 10 to 50 milliseconds.
There are three types of safety switches:
• switchboard or meter box units –installed on the main switchboard ormeter box to provide completeinstallation protection or selectedcircuit protection
• power point units – inbuilt in astandard power point to providesingle point or single circuitprotection
• portable units – suitable for use withextension cords and portable powertools.
A safety switch will not protect against all instances of electric shock. If a person comes into contact with the active and neutral conductors while handling a faulty plug or appliance, the safety switch will not detect this contact unless there is also a flow to earth.
Make sure all appliances are in good order and test your safety switch regularly by pressing the test button.
Green domes (pillars)In areas where underground power has been installed a pillar or ‘green dome’ is placed just inside the property boundary. The green dome contains live electrical wires and should be treated with a high degree of caution, particularly when performing work nearby.
If you make contact with a green dome or notice any damage, make the safe call to Western Power on 13 13 51.
• Never touch exposed wires andreport any damage to WesternPower immediately on 13 13 51.
• Underground cables from thegreen dome to the house are privateand not shown on Dial Before YouDig plans.
• Green domes should be keptvertically unimpeded and have a500mm exclusion zone around thebase of the unit to allow forauthorised access.
• Keep shrubbery well away, andensure that the access to the greendome is maintained and free fromobstructions. The ground levelshould not be raised to a level wherethe green dome is buried.
Electrical assets around homes
Private underground cables from the green dome to the house are not shown on Dial Before You Dig plans.
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NETWORK CABLE (PROVIDED BY NETWORK
OPERATOR)
NETWORK
ROAD RESERVE
PRIVATE UNDERGROUND CABLE
POINT OF SUPPLY
SERVICEPILLAR
PROPERTYBOUNDARY
MAINSWITCH-BOARD
Western Power requires unimpeded access to green domes. Ensure the area is kept free from obstructions and do not change the ground level.
Private underground cables
36 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Every year, storms and bushfires affect people and their properties in Western Australia. There are steps you can take to minimise the impact they cause to you and your home.When trees come into contact with powerlines, they can cause power failures, bushfires and serious accidents.
Trees and powerlinesHome owners and occupiers are responsible for ensuring trees on their property stay clear of powerlines all year round. Tenants should check to see if tree maintenance is covered in their rental agreement or if their landlord is responsible.
Local councils are usually responsible for trimming trees on street verges. If you see a tree on the street verge growing too close to powerlines, immediately phone your local council.
The clearance zones may vary in your area depending on the type of conductor used to transport electricity, the fire risk of the area and the distance between two poles. Allow for reasonable regrowth when trimming your trees, so they can be maintained outside the clearance zones all year round. In urban areas, the minimum clearances are typically 2.5m to the side and 2m below, while in semi-rural and rural areas the minimum clearances are typically 4m to the side and 2.5m below.
For properties with an overhead service connection, the minimum clearance distance required around the insulated low voltage service line is 300mm.
Overhanging branchesBranches must not overhang powerlines at all – the area must be clear to the sky.
Hiring a tree pruner or arboristIf you need to remove vegetation near the network, only engage a qualified arborist that is accredited to work near the Western Power network.
It is very dangerous to trim trees anywhere near powerlines. For further information, contact The Tree Guild of WA treeguildwa.asn.au
Recommended tree speciesBy selecting appropriate plants for your property, you can reduce the need for pruning and save both time and money. You should avoid planting next to powerlines, or choose a low growing species that won’t encroach on the clearance zones for your area.
Visit westernpower.com.au to find a list of plants which are more suitable for areas served by overhead powerlines. Your local nursery can also help you choose the perfect plant for your environment.
Storm preparationPrepare for storms by putting away or securing loose materials. Wind borne debris can blow into overhead powerlines and disrupt power supply.
During a storm, power outages are mostly caused by strong winds blowing debris and vegetation into powerlines and lightning striking network equipment. In addition to keeping trees clear of powerlines all year round, you can make your home ‘storm ready’ by clearing debris and securing loose objects around your home.
Are you bushfire ready? Bushfires happen every summer and they can start without warning. If you live in or near the bush, fire is a real risk to you and your family.
Everyone in the entire community – emergency services, government agencies and residents alike – is responsible for making sure that areas at risk are adequately prepared for the bushfire season.
Western Power has partnered with the Department of Fire and Emergency Services, the Department of Parks and Wildlife and the Department of Premier and Cabinet to share essential resources and information so you can start preparing your home to make it as safe as possible.
For ways to prepare your property for bushfire season visit areyouready.wa.gov.au
Seasonal safety
If you see a fallen powerline following a storm or bushfire stay well clear and make the safe call to Western Power’s 24/7 emergency line on 13 13 51.
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SPACE
2.5m
RE
GR
OW
TH
PR
OP
ER
TY B
OU
ND
AR
Y
2m
OWNERS AND OCCUPIERS ARE RESPONSIBLEFOR TREES ON PRIVATE PROPERTY
LOCAL COUNCIL AND WESTERN POWER ARERESPONSIBLE FOR TREES IN PUBLIC SPACE
X
Case Study – Vegetation management
Julie owns a property in the Perth metropolitan area and receives a letter from Western Power advising her that a tree on her property is too close to the powerline. The branches are within the 2.5m clearance zone and are a safety
risk. The letter advises that Julie must have the tree pruned within 40 days and that if she fails to do so, Western Power will have a contractor perform the work at her expense, which may cost more than if she had arranged it directly. To avoid this, Julie contacts a
qualified arborist to prune the branches which are close to network assets. Julie then instructs the arborist to prune the tree back further than the 2.5m clearance to allow for regrowth.
Vegetation clearance zones in urban areas
38 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Additional information
Useful documents
• WA Electrical Requirements 2014
• Underground Distribution Scheme Manual
• Western Australian Distribution Connections Manual
Reporting vandalism and suspicious behaviour
Electricity is dangerous. If you witness vandalism or suspicious behaviour on or near the Western Power network, contact us on
13 13 51or contact the WA Police on
13 14 44 or crimestoppers.com.au.
Other resources
EnergySafety
commerce.wa.gov.au/energysafetyWorkSafe WA
commerce.wa.gov.au/worksafeSafe Work Australia
safeworkaustralia.gov.auTraining
pts-training.com.auPower Training Services (PTS) is Western Power’s registered training organisation. PTS provides a range of structured training solutions including inductions for operational personnel and other competency based assessments.
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Working safely around theWestern Power network
Designed to help you and your business to stay safe when working around network assets. Sessions can be tailored to your business and are held at your place of work.
Discussion topics can include:
• How to plan for works near underground and overhead electricity network assets
• Danger zones and clearances
• Authorisations and permits
• Requests for asset information
• Oversized vehicle movements
• Case studies
• Due diligence and duty of care obligations
• What to do in case of an emergency.
Free InformationSessions
@westernpowerwa /westernpowerwa /western-power /westernpowerwa
For bookings: [email protected]
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40 westernpower.com.au | Emergency 13 13 51 | Enquiries 13 10 87
Notes
Availability of this report in other formats
Copies of this report are available from our website westernpower.com.au or you can call us on 13 10 87 to request it in an alternative format.
Electricity Networks Corporation trading as Western Power
ABN 18 540 492 861
Contact details:
T 13 10 87 TTY 1800 13 13 51 TIS 13 14 50 F (08) 9225 2660 E [email protected] W westernpower.com.au
