The two are in luck this time. At the Henderson primary substation close to the city of Auckland in New Zealand, the duo are given four days to service the multiple diverter switch inserts of a 100 MVA transformer and to replace its MA7 motor-drive unit manufactured in 1973 with a state-of-the-art TAPMOTION® ED motor-drive unit. Regular and careful maintenance could keep the tap changers installed here in operation for many years to come.

It's a balmy 25 °C autumn day without a cloud in the sky. Alan and Grant are working in an airy workshop at the primary substation. "A luxury," says Grant while he patiently removes the diverter switch insert from an OILTAP®. "I prefer it when it's cool." Grant neatly arranges the switch components and the diverter switch housing on his workbench, then carefully replaces the copper contacts and replaces the braided leads with new ones. Everything is done carefully and cautiously, which is just as well since Alan simultaneously oversees the winching out of another diverter switch insert that needs complete refurbishment. Altogether, the transformer has three on-load tap-changers and they all need servicing. Alan watches as the device is lifted out of the top of the oil compartment by a cable winch. He then carefully inspects the diverter switch insert once it has been lowered to the concrete floor.

"We have quite a bit of responsibility here," says Alan Brown. "When the restored transformer is put back into commission, we know that we have done our job well and correctly." Alan has been working as a service technician for MR for 18 years. "In a lot of companies, you are just a number but at MR you feel like you're part of the family," he says while summing up his experience.

His son Grant has just recently returned to Australia from a four-week training session in Regensburg for his Premium Service Provider certification. Grant has been with the company for five years since joining MR straight out of school. "I prefer working as a service technician over sitting in front of a computer," he explains. "Sometimes I just see Alan as a work colleague, not a dad. Someone you would like to get a beer with when the job is done."

The enormous Hatebur and Hasenclever hot-forging presses used at Hay Speed Umformtechnik GmbH in Lüchow exert a force in excess of 20,000 N on the red-hot bar stock in order to split it and shape one truck or car component after another in a matter of seconds. Eight ring-rolling mils roll many forged parts to even larger diameters. Each of these systems is switched on and off again several times a day, requiring huge amounts of reactive power when powering up and during operation. When Hay Speed last expanded its fleet of machines, it encountered a problem.

The shift to renewables in the district of Dannenberg, most of which is rural, is gathering pace: Hundreds of photovoltaic systems are feeding environmentally-friendly electricity into the grid of the region's largest electricity provider. When everything is running smoothly, the provider can ensure the grid quality needed for the many connected localities. But expanded production capacity at Hay Speed jeopardized this. Of late, each time the company's systems were started up they caused peaks in voltage in the superordinate grid which couldn't be compensated for. Several times, this had forced the electricity provider to switch off all photovoltaic systems. The owners of these systems and the electricity provider itself rightly demanded that Hay Speed resolve the problem and do it quickly.

A project team from MR designed two reactive power compensation systems for Hay Speed to quickly and reliably compensate for the voltage peaks produced by the switching operations of the large inductive loads. The individually constructed MR hybrid solutions each comprise a pure medium-voltage section for the base load and a low-voltage system of thyristor-controlled stages to compensate for dynamic voltage fluctuations; in each case a step-up transformer raises the voltage from 690 V to 20,000 V.

The systems are installed outside the HAY Speed factory in protective concrete stations. Since they were commissioned, the voltage fluctuation problems have been a thing of the past. Another benefit is paying dividends too. Reactive power doesn't cost the company anything any more because it takes up no more than a third of the free allocation provided by the grid operator.

POWER QUALITY BY MR Wherever rapid changes in load dynamically affect the voltage at the connection point or wherever very sensitive voltage regulation is needed, dynamic compensation systems from MR provide an effective remedy.

In the past, airplanes waiting at the boarding bridges at the Munich airport had to provide air-conditioning themselves. They operated their own auxiliary power units to supply this air. These units burn kerosene, expel large amounts of carbon dioxide and are very noisy. Now, the airport operators are changing course. By mid-year, 64 stationary, environmentally compatible systems are going into operation to supply heat and cooling to docked aircraft, eliminating the need to run the auxiliary power units. The new pre-conditioned air systems can filter and condense outside air directly at the parked position near the building, heating or cooling it depending on what is needed. The processed air then travels into the aircraft cabin through an insulated hose.

A significant component of the PCA systems are the air handling units (AHU), each of which has three drives.  Six-pulse frequency converters regulate their speed. These converters cause current harmonics, which, left unfiltered, would jeopardize the safety of other electronic components. GRIDCON® ACF active filters from MR solve the problem. Modularly designed filters have been adapted to the respective AHU power rating classes and are mostly kept in outdoor air-conditioned housing units designed specifically for this purpose. The MR active filters maintain the voltage quality throughout the airport power grid and ensure an error-free power supply at all points of consumption.

With this solution, the MR experts in the area of Power Quality beat out well-known competitors in a complex bidding process. Their precisely calculated, cost-effective filter design and their impressive service concept were very well received. Regular operation of the first PCA system began in 2014, only a few days after the contract was granted. After a one-week test run, the German Technical Inspection Association (TÜV) confirmed that compliance with all rigorous limit values had been consistently achieved.

GRIDCON® ACF MR active filters take the strain off the power grid, extend the service life of equipment, and improve the safety of industrial facilities. Where current harmonics develop, complex control methods generate current which counteracts the distorted load current and supplements the grid power to become a pure sinusoidal curve. The interfering current harmonics are eliminated and the voltage quality is improved considerably.

Download flyer for industrial version of the Gridcon® ACF

In 1925, when Dr. Bernhard Jansen patented the mechanism he had invented for continuously controlling electric voltage under load, this was the start of a new era – in energy technology and the history of MR.

Since then, MR has been setting standards in the development and maintenance of measurement and control technology. This is demonstrated by the fact that 80 percent of the 250,000 on-load tap-changers sold over the decades are still in use today.

MR recently obtained some impressive examples of the extreme longevity of its products in a customer survey. Around 10,000 customers the world over were asked to help find the oldest MR tap changers still working today. Responses and evidence in the form of photos, certificates, and name plates flooded in from Africa, Asia, Australia, North and South America, and Europe. Some highlights:

  • OILTAP® DIII, constructed 1950, used in the Uniper oil-fired power plant in Ingolstadt
    Our champion – no MR tap changer still in operation today can rival its age. The Uniper power plant is hugely important as a standby plant for Germany's power supply: It helps to maintain voltage and generate reactive power. In times of extreme cold or if major power plants fail, it acts as an "emergency service in the transmission grid" to close the supply gaps. The two generating units each have an output of 386 MW and the plant's five large transformers are checked on a regular basis.
  • OILTAP® DIII, constructed 1954, used by the Jansen group of power plants in Pfreimd
    The Jansen group of power plants in Upper Palatinate was constructed and started up following plans produced by MR's founder Dr. Bernhard Jansen between 1951 and 1961. It is one of the most important pump storage power plants in Germany, supplying valuable control energy. The MR on-load tap-changer is installed in one of the two grid transformers of the pump storage plant. In September 2015 the tap changer was analyzed by MR using the TAPSCAN® VAM procedure: After 61 years, it is still working as reliably as on day one.

Made for generations: Tap changers from MR





Allgäuer Überlandwerk and Maschinenfabrik Reinhausen have been working together for decades. For this reason, the phase-shifter transformer at the substation in Zell has been equipped with MR components since its initial commissioning. "We have established a very trusting relationship over the years," says Engelbert Sommer, Team Leader of Maintenance at AÜW. Logically, when awarding the contract for the comprehensive modernization, the company also chose to put its trust in the expertise and service of MR in all matters related to technology and project management. Only eight months passed between the awarding of the contract in early 2015 and the re-commissioning of the phase shifter in August.

The priority of the retrofit project was to replace the two on-load tap-changers for the in-phase and phase-shifted regulation. New state-of-the-art VACUTAP® on-load tap-changers with vacuum technology now operate in the place of the previous tap changers with conventional oil switching technology. The replaced phase-shifted regulator had switched reliably more than 800,000 times with standard maintenance intervals.  "Since the phase angles of the AÜW and VKW networks are constantly changing, it was subjected to a great amount of stress," explains Sommer. "Thanks to the vacuum technology which has now been introduced, we can achieve a significantly higher number of tap-change operations at extended maintenance intervals. This reduces operating costs and increases transformer availability."

Moreover, a newly installed TAPCON® voltage regulator with ISM® technology has taken over all control and regulation tasks and three TAPMOTION® ED motor-drive units, which have also been newly installed, ensure safe and reliable operation of the tap changer and the de-energized tap-changer.

The drives and voltage regulators were extensively tested under real-world conditions at MR's high-technology test center in Regensburg (Germany) prior to the retrofitting process. The Factory Acceptance Test (FAT) was also carried out subsequently in Regensburg in cooperation with AÜW. During the commissioning in Zell, the regulation and interaction of the entire system was jointly accepted with AÜW and approved by the MR specialists. "Also in regard to this comprehensive modernization process, we were once again very satisfied with the professional consultation and implementation," concludes Sommer.

RETROFIT: SOLUTIONS FOR A LONGER SERVICE LIFE The maximum service life for power transformers used to be 40 years. Today, some achieve a service life of more than 60 years. After a certain period of operation, it may make economic sense to replace components such as on-load tap-changers, drives, measurement and regulation technology or cooling systems. Where desired, Maschinenfabrik Reinhausen retrofits entire transformers with maintenance-free components. MR does this by combining all services into a total package and also by assuming the entire project management for its customers.

"Service and retrofit" brochure as a download

Hamburg's sewage treatment plant used to be one of the biggest consumers of energy in the city, but today it's fully self-sufficient. It is currently the only sewage treatment plant in Germany to produce more energy than it needs – and it does this in an environmentally-sound way from digester gas together with wind turbines, photovoltaics, and a combined heat and power plant. Hamburg Wasser supplies excess energy to the grid. The company modernized all the electrotechnology for the sewage treatment plant's centrifuges in a retrofit project completed in November 2014. To keep the power network free of harmonics, the company fitted four GRIDCON® ACF active filters from MR.

"The main criterion applied in finding the right active filters was a manufacturer with solutions suited to line voltages of 400 VAC and 690 VAC," says Horst Oehlert, the responsible project engineer at Hamburg Wasser. Working with a local supplier, MR managed to win the contract with its GRIDCON® ACF because this active filter is the only one on the market to offer the performance features required by Hamburg Wasser. Another selling point was the GRIDCON® ACF concept with up to four modules per cabinet, which allows the compensation rating to be designed to meet requirements and gradually expanded if required. The standardized components reduce costs and can be combined economically with systems for passive reactive power compensation.

Industrial version of the GRIDCON® ACF
One of the focal points of work in MR's Power Quality division is reducing harmonics and compensating for reactive power in public and industrial distribution grids with GRIDCON® active filters. In this work, the industrial version of the GRIDCON® ACF is the first choice for challenging compensation tasks in which reliability and safety must be ensured even outside of standard operating voltages and under demanding ambient conditions.

Download flyer for industrial version of the Gridcon® ACF

In any MR production space, you will see employees operating their machines with touchscreens. Former lathe operators and milling cutters are now well-trained experts who can reliably use the MR-CM® system. The software controls, manages and monitors the entire manufacturing process. Information no longer has to be entered by hand anywhere. Work folders are a thing of the past. And nobody ever has to wonder which tool is required for a specific work step at a certain time. That information can be read off from the workbench screens, which continually supply updated information.

Johann Hofmann manages the ValueFacturing® area at MR. Since 1991, he has systemized the flows of data and information into a paperless format, resulting in the development of MR-CM®. "The system works like a data hub," he explains. "It collects all production data and initiates their flow. All employees, machines, systems and available IT applications are integrated efficiently and unmatched consistency is ensured all the way up to corporate management." Hofmann is a fan of metaphors that help to understand complex relationships: "A mix of languages at Tower of Babel proportions reigns over machines and systems in production," he says. "MR-CM® is the suitable interpreter."

Bernd Kempa, the production manager in Regensburg, knows just how well the translation works and what the positive effects have been, "We carry out production with short set-up times, minimal downtime and no waste. MR-CM® contributes significantly to ensuring that each spoke in the wheel is in place and that every process is running free of errors." He estimates the potential savings at 20 to 30 percent. MR customers, he says, have even higher estimates.

Originally, MR-CM® was only developed for the company's own needs. Since then, however, MR has sold its innovative software solution to other companies in the metal cutting industry. There are already 14 companies using it, with more soon to come. "Pressure is growing for many companies to establish Industry 4.0 solutions," says Johann Hofmann. Relieving this pressure for MR makes him just as happy as when Reinhausen received the first Industry 4.0 award in 2013.


Our vision is to make the intelligent networking of production data a new industry standard in metal cutting. This is best achieved using MR-CM®, our assistance system tried-and-tested in the industry. By using MR-CM®, any company in the metal cutting industry can optimize its future production in terms of cost-efficiency, technology, personnel and professionalism.

The ValueFacturing® portfolio for MR-CM® includes potential and process analyses, project engineering, implementation, a service desk and a process desk.

ValueFacturing® online

Trade Fair Calendar
18/10/2016 22/10/2016 desktopdefault.aspx/tabid-11/1113_read-474/date-449/ 2016 WEIDMANN 15th Annual Technical Conference TC, TM/TA
24/10/2016 26/10/2016 desktopdefault.aspx/tabid-11/1113_read-475/date-450/ CEPSI 2016 Exhibition TC, TM/TA, PC
25/10/2016 27/10/2016 desktopdefault.aspx/tabid-11/1113_read-473/date-448/ POWER KAZAKSTHAN 2016 15th Kazakhstan International Energy, Electrical Equipment and Machine Building Exhibition and Forum of Power Engineers TC, TM/TA
05/11/2016 08/11/2016 desktopdefault.aspx/tabid-11/1113_read-477/date-452/ 16th Iran International Electricity Exhibition (IEE) 2016 TC, TM/TA/TS, PC
07/11/2016 08/11/2016 desktopdefault.aspx/tabid-11/1113_read-478/date-453/ VDE KONGRESS 2016 INTERNET DER DINGE
08/11/2016 11/11/2016 desktopdefault.aspx/tabid-11/1113_read-491/date-466/ Electricity 2016 The 17th Annual SEEEI Convention TC, TA
08/11/2016 10/11/2016 desktopdefault.aspx/tabid-11/1113_read-483/date-458/ GCC POWER 2016 The 12th GCC – CIGRE International Conference and 21st Exhibition for Electrical Equipment TC, TA/TM/TA
09/11/2016 11/11/2016 desktopdefault.aspx/tabid-11/1113_read-479/date-454/ IEEE CONCAPAN XXXVI Costa Rica 2016 TC, TM/TA
16/11/2016 18/11/2016 desktopdefault.aspx/tabid-11/1113_read-476/date-451/ CWIEME ISTANBUL 2016 Exhibition for coil winding, electric motor and transformer manufacturing technologies TC, TM/TA/TS
20/11/2016 23/11/2016 desktopdefault.aspx/tabid-11/1113_read-485/date-460/ CIGRE VIII WORKSPOT 2016 International Workshop on Power Transformers, equipment, substations and materials TC, TM/TA, HVT
22/11/2016 24/11/2016 desktopdefault.aspx/tabid-11/1113_read-480/date-455/ SPS | IPC | Drives 2016 27th International Exhibition for Electric Automation, Systems and Components PQ
23/11/2016 26/11/2016 desktopdefault.aspx/tabid-11/1113_read-482/date-457/ 41st IIEE Annual National Convention & EXPO 2016 TC, TM/TA/TM
23/11/2016 24/11/2016 desktopdefault.aspx/tabid-11/1113_read-481/date-456/ WAPIC 2016 West Afican Power Industry Convention TC, TM/TA
06/12/2016 09/12/2016 desktopdefault.aspx/tabid-11/1113_read-484/date-459/ ELECTRICAL NETWORKS OF RUSSIA (LEP) 2016 TC, TM/TA/TS, PC