TTemperature-wise this is one of the more comfortable jobs for Alan and Grant Brown. They are working in a primary substation of the national network operator Transpower in the mild climate of New Zealand’s capital, Wellington. At other times, the two service specialists handle the maintenance of on-load tap-changers in the torrid heat of the Australian Outback, where the ther- mometer has been known to read 60 degrees Celsius. Then, on other days, they work in regions with the same level of sweltering heat: in Papua New Guinea, Vanuatu, New Caledonia or Tahiti. In total, five service technicians at Reinhausen Australia service this giant area of operation with eight different time zones. “We are on site with the cus-tomer for about three weeks of each month,” says Alan.
PREMIUM SERVICE PROVIDERS IN ACTION
The father-son team has three days to complete the work in Wellington. For normal maintenance work this would be a considered a generous timeframe, but this job is more complex: they have to conduct a rebuild of three single-phase on-load tap-changers in the three transformers of the primary substation. Therefore, two service technicians working simultaneously are needed to complete the job on time. “Many customers require short down times during maintenance work” says 22-year-old Grant. He has been working with Reinhausen Australia for five years, becoming certified as a Premium Service Provider after a four-week training course in Regensburg in 2016.
His father Alan is an old hand in the service business. He has specialized in maintenance and repair work, retrofitting as well as diagnostics and analysis of transformers with Reinhausen Australia for 18 years. “Transpower noticed some anomalies in a measurement on the transformers. We carried out an inspection, but couldn’t find any irregularities. Nonetheless, we recommended that the on-load tap-changers and the motor-drive units be refurbished and brought up-to-date since they had been in continuous operation since 1975,” says Alan.
Assignment in Wellington: service technicians Alan and Grant Brown are always happy to work in New Zealand, since the heat is not as intense as it is in the Australian outback. (© Grant Maiden)
Alan and Grant have three days to perform maintenance on three on-load tap-changers in the Transpower primary substation. (© Grant Maiden)
They will be using a total of 120 kilograms of replacement parts in the process. (© Grant Maiden)
Grant summarizes the process: “The three transformers each contain an older style M-type on-load tap-changer which we need to rebuild and bring up to modern standards. For this process, we must completely dismantle the diverter switch units into all individual parts and then clean and inspect all mechanical and insulating components such as the transition resistors. For this job, we will be installing a new energy accumulator system and exchanging contacts and other critical components and then rebuilding the diverter-switch unit. When that’s done, maintenance for the motor-drive unit and the drive shafts are next in line.” Some 40 kilograms of spare parts per on-load tap-changer were shipped to Wellington in advance for this purpose.
The young technician has already neatly laid out the tap-changer components on a workbench together with the oil compartment. He carefully replaces the copper contacts and exchanges the old flexible leads with new ones. This is work that requires a fine touch. “It feels like there are a million parts in front of you, but there is a checklist process that helps make sure you don’t forget anything. The tap changer is a high-risk component. If it doesn’t function, the transformer doesn’t either,” says Alan, who is now monitoring the removal of the diverter-switch insert from the oil compartment of the next transformer. “There is a great deal of responsibility with this work. But when the overhauled transformer is switched back on and functions, you know you’ve done your job right,” explains the experienced service technician.
NO FEAR OF ERRORS
Neither of the two experiences nervousness or fear of errors. “They simply don’t arise, thanks to thorough, continuous training where what we learn becomes ingrained in us. You have your own routine and you know you’ve checked everything,” says Grant. It is not often that father and son are on the same assignment since service technicians are often on site alone. They are only paired up when the job is especially extensive. “I see an enormous benefit from such assignments,” says Grant, “Experience is very important in this job.”
On the last work day, Grant, secured by a harness and firmly footed on top of the transformer – assists and monitors to ensure that the last of the three refurbished diverter-switch inserts is lowered into the transformer correctly. The technicians refurbish and maintain the motor-drive units and the drive shaft on the final day as well. The last screw has been put into place mere moments before Alan cranks the connection between the drive unit and the tap changers on each transformer in order to synchronize them so that there is less than a hand crank turn between them.
Afterwards, he conducts yet another mechanical test which runs through all 13 positions. “All done,” says Alan to Grant, as the young technician packs up his equipment. Father and son are already looking forward to a relaxing weekend in Sydney. On Monday, the two have more work waiting for them. Next up is an assignment in Tasmania.
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The New Zealand transmission network operator Transpower maintains a power grid covering a total of 12,000 kilometers and operates a total of 170 primary substations with 1093 transformers. Most of the energy here comes from renewable resources: www.transpower.co.nz
The Reinhausen Australia subsidiary was founded in 1987 in Sydney and is celebrating its 30-year anniversary this year. Today, 11 employees work here, including five service technicians who take care of the entire Pacific region, in addition to Australia and New Zealand.
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