The new Wiring Regulations have been the subject of much debate in the electrical sector since their introduction in June of this year. There has been much discussion about the various protection solutions and the new standards for establishing wire systems.
An NECA member who frequently works installing wiring underneath raised levels in data centres and similar installations voiced major worries about the effects of the newly implemented rules on his work during a recent information night. In order to prevent disruption or damage to wire systems, the standard mandates a number of new standards.
Installation requirements for customer cabling
You must adhere to the procedures outlined in this industry standard for setup and upkeep. This standard specifies the minimum standards for any fixed or concealed equipment or equipment which is connected or is designed to be joined to a telecommunication system. As of the 20th of August in the same year, 2020, AS/CA S009 2019 was officially released as the normative document for the industry. Over the next 18 months, beginning on August 20, 2020, businesses are permitted to continue using the AS/CA S009 2013 standard.
FAQs About Cable Wiring System
A wiring system can be defined as a group of more conductors, cables or busbars, and all parts used to secure them in position. It also includes any mechanical protection that is provided for the conductor. The first concept that we need to understand is that the installation method will determine the classification of the wiring system. It will be either a "Wiring system likely to be disturbed" or a wiring system requiring "protection against mechanical damage".
Wiring Systems requiring protection against mechanical damage are generally cables installed in hollow walls, walls with plasterboard or similar material on either side of the wall studs. When wiring systems (cables) are installed in locations where they may reasonably be expected to be subjected to mechanical damage, you are required to provide adequate protection. This can be done by one or any combination of the following:
- Mechanical characteristics of the wiring system
- Location selected
- Provision of additional local or general mechanical protection
If additional mechanical protection is selected, appendix H of AS/NZS 3000:2018 provides an explanation of the WS classification system and practical information about what is needed to comply with each classification. Now 'What is a WS classification?' you may ask. Well, it has been around for some time and comes from another Australian Standard specifying fire and mechanical protection ratings for wiring systems.
There are some specific methods of installing wiring systems where the Wiring Rules provide additional guidance or requirements, such as;
- Wiring systems near building surfaces - Wiring systems that are fixed in position by fasteners, or held in position by thermal insulation, or by passing through an opening in a structural member concealed within 50 mm from the surface of a wall, floor, ceiling or roof.
- Exception: This requirement need not apply to wiring systems that can move freely to a point not less than 50 mm from the surface in the event of a nail or screw penetrating the cavity at the location of the wiring system.
- Wiring systems near roofing material - wiring systems passing through a structural member or are fixed in position, within 50 mm from the face of the supporting member to which the lining or roofing material is attached.
If you're looking at rewiring your home, one of the biggest factors is cost. Of course, rewiring a home is not cheap. But it's essential for the safety of your family. After all, more than 40% of residential fires in Australia are associated with electrical faults or failures caused by degraded wiring or overloading the system. Rewiring a home can involve anything from fixing up a few dodgy outlets to replacing all the wires throughout your home.
You might just be covering the essentials or thinking of the future and setting your house up for complete home automation. Since rewiring jobs are so varied, it's impossible to put a simple price tag on the project. But on average, you can expect to spend between $3,500 and $8000 to rewire a medium-sized home. This guide looks at the different factors that will impact the cost of your home rewiring and answer all those other questions you might have. So click on a section below, and let's get started.
There's no pretending rewiring a house isn't a big job. It involves pulling out all the old electrical wires and replacing them with newer, safer ones. If you're lucky, a sparky can access the wiring from outside the house or without needing to damage existing walls. Sometimes, they might have to do some damage - by removing the cladding or drilling through timber - that will be fixed up and cost out as part of the project. A home rewiring might involve replacing the wires. It will likely include additional upgrades: new sockets, power points, switches, or a new switchboard.
Underground Power Cables: Costs And Benefits
All of Australia's existing electrical infrastructure may be undergrounded, but doing so could cost up to $50 billion. After consulting with high-level distribution system executives, this estimate was arrived at conservatively through careful calculations in specific regions. Even so, it's a huge expenditure, on par with what we're currently spending on the entire country's electrical infrastructure. But, if this price is accepted, the rewards are substantial. Burying high voltage cables can be enticing in land-starved countries. In the Philippines, for instance, enough money was made from the sale of the easement on which the overhead lines were constructed such that the lines could be buried while still turning a profit.
Subdivisions in the outskirts of major cities in most Australian states are now required to have underground electricity lines installed. Each year, between 150,000 and 200,000 new residences in Australia are wired into the subterranean electrical grid. Over the course of several generations, a sizable chunk of the nation's housing stock will be connected to the ground below. Strangely enough, the outlying suburbs will have underground power, the most aesthetically beautiful and technically desirable choice. Conversely, central city neighbourhoods with high property values are significantly less likely to reap the benefits. As a result, central metropolitan districts are virtually always served by subsurface distribution networks. Yet, there are a lot of 'burbs close to the city where this hasn't happened and isn't likely to.
Inner high-value suburbs are an example, since some wealthy local officials with low debt levels have developed their own systems, sometimes trying to recoup some of the expenses from homeowners and other times just adding it to the rates. Older, established areas are unlikely to undergo significant change in the near future unless there is political and local will to do so. In addition, some power companies note that the piecemeal nature of gentrification in inner suburbs makes it impossible to sink lines throughout the entire area. Yet, utility engineers point at how the case for underground cabling has become more compelling if a proper estimate of maintenance and degradation of overhead wires is made.
The high-voltage transmission lines that must be sunk face unique difficulties and will likely cost five to 10 times as much as conventional overhead transmission lines. As a result, it should come as no surprise that only a minuscule fraction of Australia's 66 kilovolt (kV) and higher lines are buried. Only 156 kilometres of the 24 500 kilometres of wires in the lowest frequency category in just this range are buried. Just 4.6% of the 3,670 kilometre long 110 kV wires are underground. Even fewer 132, 220, 275, 330, and 500 kilovolt circuits use underground cable.
Cost, safety, technical difficulties, ways in which some towns have eliminated overhead wire, and environmental concerns are only some of the topics that will be covered in the following conversation.
Major Issues
- Few would argue with the claim that burying unsightly electrical wires makes a street or neighbourhood more appealing, but doing it on a national scale is a significant obstacle. It appears unlikely that the issue will be resolved very soon.
- Just about 7% of Australian households receive their electricity through underground wires. There is a paradox hidden in this number, which is that this convenience is available in large quantities in far-flung suburban neighbourhoods. Yet, some older suburbs near city centres have premium property values despite the presence of unattractive overhead wiring.
- All around Australia, several groups are working to extend the reach of underground power. Subdivisions built on the outskirts of major cities are often required to have subsurface electrical wiring in most states. Yet, in the grand scheme of things, it is fair to say that there is some political will to do more.
- Given the widespread distaste in Australia for TV cables stretched atop street poles and the growing wrath of local government constituents over this unsightly "invasion," a proposal to have subterranean power conduits shared with cable TV and other technologies would appear appealing at first.
- Although subterranean electricity proponents in Australia are generally open to cable TV, they are apprehensive of its rapid adoption. There are so many moving parts, they say, that it will be difficult to begin burying the power lines. Engineers note that the sharing option has not been widely discussed because of these complications.
Issues
Traffic Hazard
The rising percentage of subsurface power has been mostly motivated by concerns for safety and aesthetics. There were seven fatalities and seven hundred and forty-three injuries involving vehicles and electricity or Telstra masts in Western Australia in 1993. Vehicle collisions with utility poles result in an annual cost of $45 million, according to the South East Brisbane Electricity Company. The human cost is disregarded here. The safety component of overhead lighting has received little attention in Australia, according to one executive, because utilities virtually always obtain reimbursement for the expense of these kind of damage from vehicles' insurance companies.
Tree Hazard
When trees need to be trimmed, there is a risk of electrocution due to live wires and fallen limbs, and there are also potential hazards from storms. Increasing concerns about the safety of the current energy systems are being voiced by homeowners as they push for greener communities. Damage to electric cables from falling trees is a serious issue during storms. The ensuing anarchy is frustrating for homeowners and costly to fix for businesses. Most people don't realise how vulnerable our distribution networks are to these kinds of influences. The demand for underground power is rarely revived unless there is a big disruption.
Across the south-west of Western Australia, the whole distribution system was badly impacted in May 1994, prompting a renewed push by the State Government to move through with underground power. After the storm, large sections of the suburban and near-country distribution system were knocked out and in some cases remained out of commision for several days. Almost all of the material losses were caused by trees.
Power outages are inevitable when electricity is distributed via poles across such a vast area, as was shown by the 1994 storm and, to a lesser extent, Cyclone Alby some time previously. As an end, about a quarter of Perth's population, or 300,000 people, went without power for at least 24 hours. It took eight nights after the hurricane for some people to get back online. A population of less than fifteen million individuals live in the south-west of Western Australia, and this storm is not quite as severe as such tropical cyclones that impact Northern Australia.
200 out of 450 power line feeders were knocked out by trees, garbage, and the wind. About a thousand high voltage cables and four hundred and thirty feet of street mains were also taken out of service, along with eight hundred and fifty distribution transformers. The 1800 customer service lead-lines that ran through people's homes were also ruined. In excess of 2,000 locations, trees were either knocked over or blown into power lines. Once the storm passed, about 800 utility poles had either fallen or were bending.
The state-run utility Western Power came under fire for its handling of the situation. Western Power's restoration personnel were commended for their tenacity throughout the storm, and an official investigation found more should have been done to address such huge interruptions in the future. Wild storms in January 1991 wreaked havoc on Sydney, and similar points of view may be applied to the resulting disruptions.
The Costs Of Sinking Power Lines In An Inner Suburb
Subiaco, a neighbourhood in Perth, has undertaken an extensive effort to bury its electrical cables. Several of the lanes are only 10 metres wide, thus the elimination of poles has made a huge difference in the overall aesthetic quality of the area. Subiaco, as far as anyone can tell, is the first Australian municipality to underground without subsidies or taxes to individual homeowners. Because disagreements could arise between property owners who agreed to foot the bill or those who did not, it decided against levying fees on them. Subiaco discovered that the average value of properties in the $200,000 to $300,000 range improved by $10,000 per lot after the removal of ugly poles and the alignment of walkways and roads. Estimates for the rest of Australia are very similar. Taking into account the intangible benefits, this looks like a fair return on the $3,000–$4,000 per home needed to sink electricity cables.
Almost 35% of Subiaco's streets will be devoid of electrical cables by the beginning of 1997, the result of a programme that began 14 years ago. Throughout the last nine years, its council has spent $5.8 million, with the most recent fiscal year seeing spending of $1 million. Council administrators acknowledge that the goal of having the suburb free of utility poles by 2010 may be optimistic, given the likely decline in annual resources for the project. All homeowners who have overhead lines will appreciate the fact that it is no longer required to indiscriminately cut down street trees to make room for utility poles. The natural form of trees should be encouraged. The effectiveness of street lighting is diminished in some regions due to the density of the surrounding vegetation. But, in order to solve this issue, the Subiaco City Council has implemented rigorous lower pruning and more illumination. The use of mechanical damage-prevention techniques in electrical wiring systems
Where wiring protection is called for, an RCD with a connected load operational leftover current of 30 mA must be used to safeguard the circuit. A shunt protective device can also be made to function under fault conditions if it is protected by an earthed iron armouring, screen, covering, or inclosure. Another option for damage prevention is to equip the system with sufficient mechanical safeguards, at least to the WSX3 level.
The placement of a residual current device (RCD) is the most popular kind of protection utilised by our business, especially for lines up to 32A and in household installations. When applied to client mains and subdomains, this procedure becomes somewhat cumbersome. If you want to safeguard the sub with something other than an expensive and scarce Type "S" RCD, you'll have to make use of one of the additional techniques. However, the other elements of security are not always as easy to implement, especially when making changes to preexisting structures. Moving into a brand-new house is much simpler.
Metallic shielding, screening, covering, or enclosing is permitted. Thinner than 2mm, these need to be earthed so the short circuit safety device can function. The manufacturer suggests using an earth clip in conjunction with steel conduit or an anaconda. Steel sheets less than 2mm in thickness across the studs are suitable for use as earthed materials. Providing enough added protection at a baseline of WSX3 to prevent further damage is an option that will be rarely employed.
- To get the WSX3 certification, the wire system (cables) must be medium-duty protected against damage and pass the necessary tests in accordance with AS/NZS 3013.
- The use of any cabling system (cables) that has an unsupported width of no more than 100 mm and an additional 2.0 mm of sheet steel coverage.
- The alternative is to utilise any WSX2 system that has a sheet steel coverage of no less than 1.6 mm and a maximum unsupported width of 100 mm.
- Galvanized medium tubes meeting AS 1074 or very heavily loaded conduits meeting AS/NZS 2053 or AS/NZS 61386 are alternate options.
Amazing information. It is possible, though, that this choice will be employed in settings such as hospitals, hospitals' mains, and consumer mains and subdomains.
Conclusion
Since their introduction in June of this year, the new Wiring Rules have sparked heated controversy among electrical professionals. Concerned about how the new regulations would affect his job, a NECA member expressed serious concerns. Installation criteria for customer cabling and underground power cables are among the new standards that must be met to ensure that wire systems operate without interruption or harm. Undergrounding might cost up to $50 billion, but businesses are allowed to continue utilising the AS/CA S009 2013 standard for installation and maintenance. It may seem appealing to countries who are short on land to bury high voltage wires.
Most Australian governments currently mandate the installation of underground power lines in new subdivisions on the fringes of major cities. Subsurface distribution networks are common in affluent central city neighbourhoods, although there are many outer suburbs that have not been connected to the city's infrastructure and are not likely to be connected in the near future. The submerged high-voltage transmission lines have their own set of challenges and are expected to cost five to ten times as much as traditional overhead lines. We also talk about how much it would cost, the potential risks, the technical challenges, the ways that some communities have gotten rid of overhead wire, and the environmental issues. In Australia, 7 percent of homes get their power through subterranean cables, and that number is growing.
Suburbs further from city centres have greater access to this amenity, while some older suburbs closer to city centres have higher property values despite the presence of unsightly overhead wiring. Most states mandate underground electrical wiring for new subdivisions constructed on the fringes of major cities, but there is political will to expand this requirement. Although the idea of sharing underground power conduits with cable TV and other technologies seems intriguing, getting started on burying the power lines will be challenging due to the many moving elements involved. Both vehicle traffic and tree branches pose significant risks.
The most critical information is centred on the possible dangers of storms, including the dangers of electrocution from live wires and falling trees. Large portions of the suburban and near-country distribution system were knocked out and out of commision for several days when a tropical cyclone hit the south-west of Western Australia in May 1994. Trees, trash, and the wind took off 200 of 450 feeders, damaging 1,000 high-voltage wires and 430 feet of street mains. At nearly 2,000 spots, trees had been uprooted or thrown across electrical lines, and at least 800 utility poles had fallen or were leaning dangerously. Underground electricity is rarely in demand again unless there is a major disruption.
Subiaco is a suburb of Perth that has made significant efforts to bury its electrical lines; as a result, 35% of its streets were cable-free at the start of 1997. When it comes to Australian cities, Subiaco is the first to underground utilities without charging homeowners any sort of fee or subsidy. By cleaning up the neighbourhood and moving unsightly poles, the average value of homes in the $200,000 to $300,000 range increased by $10,000 per lot. The Subiaco City Council has instituted stricter lower pruning and more illumination, in addition to mechanical damage-prevention procedures in electrical wire systems, to address the problem of street lighting being less effective in some areas due to the density of the surrounding vegetation. A residual current device (RCD) with a connected load operating remaining current of 30 mA is required to protect the circuit, and a shunt protection device can be made to function under fault conditions if it is shielded by an earthed iron armouring, screen, covering, or inclosure.
The wire system must be medium-duty damage-protected and pass the required tests in line with AS/NZS 3013 in order to receive the WSX3 certification. Instead, you can use any WSX2 system with unsupported width up to 100 mm and sheet steel covering of at least 1.6 mm.
Content Summary
- Since their introduction in June of this year, the new Wiring Rules have sparked heated controversy among electrical professionals.
- New requirements are imposed by the standard to protect wire networks from being disrupted or damaged.
- There are a number of advantages and disadvantages to installing power cables underground.
- There has been talk about burying all of Australia's power lines, but the estimated cost is $50 billion.
- Most Australian governments currently mandate the installation of underground power lines in new subdivisions on the fringes of major cities.
- Just about 7% of homes in Australia get their power via wires buried beneath the earth.
- Many organisations around Australia are making strides towards a more widespread use of subsurface power.
- Generally speaking, most states mandate underground electrical wiring for new subdivisions constructed on the fringes of major cities.
- A proposal to have underground power conduits shared with cable TV and other technologies might seem enticing in light of the general dislike for TV cables placed atop street poles in Australia and the growing anger of local government constituents over this unsightly "invasion."
- It is a common problem during storms for trees to fall on power lines, causing disruptions.
- As a result of widespread damage to the distribution system in May 1994 across the south-west of Western Australia, the State Government has revived its campaign to install underground power.
- One hundred thousand individuals, or almost a fourth of Perth's population, spent at least 24 hours without electricity as a result.
- To the best of our knowledge, Subiaco is the first Australian municipality to underground without charging homeowners a premium.
- The 14-year-long programme to remove electrical lines from the streets of Subiaco will be completed by the start of 1997, clearing about 35% of the neighborhood's streets of their clutter.
- Nonetheless, the Subiaco City Council has instituted stricter tree trimming and increased lighting to combat the problem.