5 MVA Transformer Urgent Inspection and Repair

Ampcontrol provided a review of oil analysis reports, onsite inspection and urgent workshop repair, of a production critical 5MVA transformer to get it back into service as soon as possible.

Background

The customer, a mine in Southern Queensland has been supplying coal to local power stations in the area for over thirty years. The mine approached Ampcontrol due to concerns about the condition of a production critical 5MVA transformer on their plant.

Problem

Our review of their latest oil analysis results indicated the occurrence of a serious T3 Thermal Fault – high temperature heating (>700ºC). The presence of acetylene & elevated levels of heating gases in the sample pointed to the severity of the fault and possible involvement of electrical contacts. Transformer specialists from Ampcontrol in Mackay went onsite and conducted an internal inspection. Oil was drained to the top of the core and the inspection lid removed. The team identified what could have contributed to the elevated gassing in the DGA results. The paper on 1-off LV lead connection had significantly carbonised, and as such we recommended immediate action to further investigate the problem. The Transformer was immediately transported to Ampcontrol’s transformer facility in Newcastle, NSW to carry out further inspections and the necessary repairs.The internal inspection identified a partly unsecured and dislodged coil clamp block under the top core frame. A small amount of arcing discharge between some of the core steel sheets in the outermost step of the top yoke, located in the A-phase LV side of the transformer was also found. Four hot joints in the LV leads were found, and these were the most likely cause of high-temperature fault gasses in the oil. The hot joint observed on C-phase was quite severe as the heat had travelled down close to where the LV leads exit the winding. We believed the hot joints were caused by inadequate preparation when crimping the copper lug to the aluminium winding conductor. Ampcontrol provided both onsite and workshop specialist transformer services at short notice.Our detailed workshop repair program included replacement of damaged and incompatible materials that contributed to the heating problem, and a partial rebuild of the clamping structure. The core and coil assembly were processed in a vacuum oven, followed by vacuum filling and hot oil circulation to further ‘filter’ the liquid insulation of water, gasses and particles/ debris. Electrical testing was conducted in our Newcastle workshop before being transported back to site.

Achievements

  • Reviewed oil analysis results and provided remote technical support to help manage a serious problem with a production critical transformer.
  • Provided onsite emergency support at short notice including an internal inspection that identified possible causes of the problem.
  • Conducted a workshop internal inspection and detanking of core at short notice to further investigate the causes of the problem.
  • Undertook a repair program that put the transformer back into safe operation quickly.

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Ampcontrol Manufactures 50MVA Power Transformer

The Project

To take their current production from 6.4Mta to 7.5Mta, a central New South Wales mine engaged Ampcontrol to design, manufacture and install high voltage infrastructure. The 132/11kV project included a 40/50MVA transformer, c/w 11kV substation, 3000A 11kV switchboard and associated protection system.

As part of the project Ampcontrol designed, manufactured and tested a 40/50MVA 132/11kV transformer, with a final fully assembled weight of 85 Tonnes.

The transformer was fully tested in house in Ampcontrol’s transformer facility, before being filled with oil above the core and coil assembly for transport, to the mine, where site erection work was undertaken by Ampcontrol’s High Voltage Service team.

The transformer will be energised at a later date during major site shutdown works.

Specifications

  • Rating: 40/50MVA
  • Voltage ratio: 132/11kV
  • Vector group: Dyn11
  • Cooling: ONAN/ONAF
  • Tap changer: on load tap changer – Vacuum type on load tap changer supplied by Mischinenfabrik Reinhausen GmbJ (MR), Regensburg, Germany.
  • Oil: filled with inhibited transformer oil as per IEC60296
  • Transformer tested as per AS/NZS 600076

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Ensuring Site Continuity at a Hydroelectric Power Station

Ampcontrol recently supplied high voltage switchgear on a hire basis to a hydroelectric power station in a major capital city to ensure site continuity.

This power station provides hydroelectric energy generation and storage, with the pump system supplying water to the local drinking water supply.

The power station contains two 8kV 46MW hydroelectric generator pumps. During a recent service, one of the pumps were sent for overhaul, meaning that only a single pump was available for service to supply a contracted amount of water.

During commissioning of a new motor drive, issues were encountered with the drive control. This meant that switchgear had to be sourced urgently to return the only operable pump to service.

The customer made an urgent request to Ampcontrol to hire high voltage switchgear to assist with the pump start-up power switching and control scheme.

Ampcontrol’s in stock switchgear was modified at short notice to integrate into the power station control system allowing the pump startup sequence to be controlled and monitored automatically.

Ampcontrol supplied a hire unit with three 11kV, 630A vacuum circuit breakers inside a container, tested and modified to integrate with the power station control system within 3 days of the customer order.

The job was delivered to site where a team of seven Ampcontrol staff completed the installation and commissioning over a five day period onsite.

Following installation and commissioning, the customer ordered an additional 3.3kV circuit breaker and specialised medium voltage screened cable which were modified to suit the customers’
requirements and delivered within 3 days.

Throughout the project Ampcontrol ensured that equipment, parts, materials, site staff, SWMS, Risk Assessments and access permits were made available in the shortest timeframes possible to ensure customer downtime was minimised.

Following the successful rollout of this project the customer purchased the equipment which will remain onsite.

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Re-thinking Traditional Fixed Infrastructure

Traditionally, the construction of permanent electrical infrastructure has been thought of as just that, permanent. It’s constructed using time consuming and site labour intensive bricks and mortar construction techniques. But does it need to be? What if fixed infrastructure was in fact relocatable? What benefits would this bring to infrastructure projects?

Typical Applications

Surface and underground mines typically employ relocatable power equipment. They do so to accommodate the dynamic nature of a mine site, where the electrical system must move, regularly extended and be rapidly deployed as mining progresses. This equipment is invariably relocatable, compact and relatively high voltage. In addition, it’s designed for transport with minimal disassembly and reassembly with an aim to streamline site works.

Mining substation

A typical relocatable substation used in above ground mining applications 

Non-Typical Applications

We’ve seen this type of relocatable and rapidly deployable power equipment becoming used in a range of non-typical applications. At Australia’s two largest solar farms in Broken Hill and Nyngan, Ampcontrol completed 117 identical power conversion skids housing control panels, inverters and transformers.

Using the rapidly deployable model these electrical skids were fully manufactured and assembled at Ampcontrol’s workshops before being transferred to site as complete units. This resulted in significantly simplified onsite works and ensured the skids could be delivered at a rate of four per week.

Modular electrical equipmentPower conversion skids being manufactured in Ampcontrol’s workshops

Power conversion skids

Power conversion skids installed at the solar farms 

Due to the dynamic nature of their environment, the tunnelling industry is familiar with rapidly deployable power equipment during the construction phase. It is not however typically used for permanent electrical infrastructure within tunnels post construction.

Westconnex, Australia’s largest infrastructure project, recently implemented this rapidly deployable style of infrastructure for their 46 Electrical Equipment Rooms (EERs). The EERs all included a transformer, switches, circuits and communication systems but were all individual in design, dependent on location and requirements.

These EERs were manufactured in Ampcontrol’s Tomago NSW workshops before being transported to the Sydney tunnelling site at a rate of two rooms per week.

Westconnex was the first tunnelling project in Australia where EERs were manufactured offsite and installed directly into the tunnel, compared to the traditional method of building them in-situ. This approach resulted in significantly reduced and simplified civil works, and faster installation with fewer people underground.

relocatable power infrastructure Power infrastructure tunnellingEERs being delivered and installed in the Westconnex tunnels

The Benefits

Manufacturing in a dedicated workshop enables many variables to be easily controlled, ensuring a safer, better cost controlled and time managed build.

Safety improvements

  • Minimal staff required for underground siteworks, installation and commissioning
  • Construction managed offsite in a controlled environment where risks can be better managed

Cost control

  • Manufacturing efficiencies are gained through modularised repeated assemblies, designed specifically for a workshop environment

Time management

  • Fast install and commissioning
  • Manufacturing, transport, installation and commissioning can all happen simultaneously ensuring project construction continues unimpeded by siteworks

Rapidly deployable relocatable equipment for fixed applications is a viable option for a variety of industries and applications. Ampcontrol is expertly positioned and experienced in the design, manufacture, testing, installation and commissioning of this type of equipment across typical and non-typical applications.

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100 Australian Engineering Leaders Featuring Ampcontrol Co-Founder

This year Engineers Australia turns 100. In celebration they are showcasing Australian Engineering Leaders who “pushed boundaries, defied odds, and came up with innovations that no-one could have imagined 100 years ago”.

At Ampcontrol we’re proud our co-founder Peter Cockbain is featured in the Engineers Australia publication “Anything is Possible 100 Australian Engineering Leaders”. The book celebrates 100 Australian engineers past and present who have made a difference.

Peter is featured as a leader in manufacturing and strong champion of the Australian advanced manufacturing industry as well as one of the founders of the international business that is Ampcontrol. He’s in esteemed company, featured alongside engineering leaders such as Sir Peter Nicol Russell whom Australia’s highest recognition of individual engineering achievement is named and Sir Ernest Fisk who introduced Australians to the airwaves.

Peter joined Engineers Australia in 1966 and started volunteering around 50 years ago to return some of the benefits that Engineers Australia had given him. Peter’s voluntary contributions include National President of Engineers Australia in 2006, a member of the University of Newcastle Council, the Engineering Faculty Advisory Board and the University Student Services Board, a member of the Prime Minister’s Science, Engineering and Innovation Council, Senator Kim Carr’s Future Manufacturing Industry Innovation Council, a Director of Standards Australia and Chairman of the Standards Development Committee. In 2015, he received a Member of the Order of Australia honour for his significant contribution to the mining and energy sectors and professional organisations. Find out more about Peter’s voluntary roles.

Congratulations to Peter and all of the 100 Australian engineers past and present, who have the honour of being included in this publication.

Ampcontrol Finalists in the Hunter Safety Awards!

Celebrating its fifth year, the Hunter Safety Awards have announced the 2020 finalists who have demonstrated positive approaches to Work, Health and Safety (WHS) in their workplace. Ampcontrol is represented as finalists in three categories.

  • Best WHS Improvement Award (Large Organisation)
  • Best Health and Wellbeing Award (Large Organisation)
  • WHS Champion of the Year – Carolyn Parish

The Hunter Safety Awards was launched in 2016 to highlight and acknowledge companies and individuals within the Hunter region who demonstrate best-practice and innovative approaches when it comes to workplace health and safety. Find out more about the 2020 Hunter Safety Awards 

Let’s get flexible – how plug and play cables could be the secret to securing mining communications

In a world of deeper mines, rising energy costs and infrastructure shortages, mining companies remain under exceptional pressure to control costs, heighten efficiency and improve safety performance. Although there is no single easy solution, it is becoming increasingly apparent that technology will play a growing role in the mining industry of the future.

As the fourth industrial revolution progresses, data connectivity is taking a more pivotal role – information from sensors, data-heavy automation solutions and data analytics must be conveyed across large distances and through challenging environments. The mining industry is deploying automation technologies at a rapid rate, meaning the demand for flexible and high-bandwidth communication is soaring.

Fiber optic networks are a critical enabler of this bandwidth, providing a bridge between devices, data processing units and control systems which are increasingly being adopted across many sectors. With fiber optics come additional benefits including immunity to electromagnetic fields, galvanic insulation and future-proof advantages with regards to bandwidth extension. But mining environments pose a risk for the physical integrity of these networks.

With mines reliant on their communications infrastructure for essential safety systems and the critical link between operations underground and those working on the surface, network failure is not an option. So how can mining companies ensure high-performance, quality, reliable and long-life solutions that enable seamless underground communication networks?

 

Rapid and easy to deploy 

In mining, production depends on full and continuous availability of the network to ensure reliable communication with sensors, between machines and workers. Any damage to a mine’s fiber optic network, therefore, translates into significant expense and potential safety hazards. Hitherto, fixing damage was time-consuming and dependent on the arrival of a qualified fiber optic technician with suitable and calibrated termination tools and components.

Today, while network failure and damage cannot be avoided altogether, mining companies are able to massively reduce downtime as a result of network outages. This is due to a new solution created jointly by HUBER+SUHNER and Ampcontrol to enable rapid deployment of fiber optic networks in mines.

Leveraging the extensive experience of HUBER+SUHNER in providing solutions for optical connectivity in harsh environment conditions and Ampcontrol’s renowned expertise in providing integrated electrical and electronic equipment and power solutions for mines in Australia and elsewhere, the harsh environment reticulated fiber optic solution – H3RO – enables fast deployment of fiber optic networks in mines. The solution is based on standardised components that can be combined in a tool-box like manner. The solution’s modularity implies it is flexible in design, allowing for dynamic and easy modification and expansion of network architectures. This is critical in mines, where the network topology changes continuously as the mine grows/moves along. Also, because mine workers are frequently unskilled in communication technologies, simplicity of use and robustness against mishandling is essential.

Putting the theory into practice

The benefits brought by solutions of the two companies have been experienced by many mining customers, one reference case being an underground gold and copper mine in Western NSW, Australia when an existing communications cable was severed.

H3RO was deployed from an existing FOBOT (fiber optic break-out terminal) panel for a distance over 1 km along the roof, through a number of vertical drops and into another existing FOBOT enclosure. The solution’s plug and play cables and modular components made it the ideal choice for the fast deployment of cabling for this work. The IP68 connectors and bulkheads allowed a neat, maintainable solution that integrated seamlessly with off-the-shelf IP68 bulkheads and pigtails to match the existing patch panels.

Due to the modular installation and low-loss connectors, network expansion and recovery from similar incidents in the future is now hassle-free. The entire cable run consists of a quantity of four 260 m 12-core H3RO cables, making swapping any section out easy, rather than replacing the entire run or requiring expensive and time-consuming fiber field splicing in the mine’s harsh environment. The H3RO cables allow the addition of break out terminals (BOTs) at any cable joint allowing standardised and flexible network access/extension as requirements evolve.

H3RO components are manufactured in state-of-the-art facilities, all items are tested and shipped with quality reports. This offers a more cost effective, reliable and risk-free solution to field splicing in an underground mine where constraints such as time, darkness and the dirty working environment all affect the quality of the job.

Find out more about H3RO 

Replacement Transformers On The Road To Western Australia

During the latter part of 2018, Ampcontrol was approached to supply a range of drop-in replacement transformers as part of a major upgrade of an iron ore mine in Western Australia.

This mine was looking to source reliable and robust equipment that was proven under onerous site conditions, including various levels of harmonics, ensuring continuity of supply and maximum product lifespan. Ampcontrol’s proven transformer designs and manufacturing credentials made us the ideal supplier.

In 2019 Ampcontrol delivered 20 transformers to the project ranging from 1000kVA 33kV to 10,000kVA 33kV all designed to suit existing mounting positions and cable connections within 5mm tolerances.

Production has been staggered to minimise site shutdown requirements and will be ongoing into 2020 when another 31 transformers will be manufactured, as well as routine and type testing to AS/NZS 60076, in our Tomago NSW transformer facility.

Measuring the response time of gas detectors

Just twelve months after completing his university studies, Ampcontrol Graduate Engineer Thomas Steigler will travel to Tokyo, Japan, next week to deliver the findings of his research work to the international IEC Gas Detector Standards Committee MT 60079-29.

Thomas has been studying innovative ways to measure the response time of gas detectors, and has developed a test procedure that is three to five times more repeatable than any previously used methods. This is significant as repeatability is the most important attribute of any performance test.

The results of Thomas’ work will lead to revisions in the international standards for gas detectors. These same standards will eventually be adopted in Australia, against which Ampcontrol’s Gasguard products will be measured.

Group Engineering Manager Ian Webster said “The invitation extended to Thomas to present his work is an honour for any researcher, let alone one who has only been working in the area for eight months.” He added “It is also a great credit to Ampcontrol that its Graduate Program allows and encourages young professionals to engage in ground breaking research that benefits both the company and the gas detection industry globally.”