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

"Creating a corporate culture is a long-term and complex process," says Roan de Bock, who coordinates and evaluates the regular employee surveys as the head of personnel marketing. The surveys are no longer limited to Germany – they are also being conducted for all foreign MR subsidiaries throughout the world in turn. "Conducting the surveys on a continual basis helps us to define our position: time and again it shows us where we stand compared to other companies, what progress we have already made, and what our employees still see as potential for improvement."

The "Great Place to Work" questionnaire generally focuses on central issues such as identifying with the work you do and the company you work for, work-life balance, appreciation, or promoting health. Additionally, MR encourages participants to assess the professional expertise and social competency of their immediate supervisors. Problems which come to light are then resolved at a departmental level.

"At MR there is a sense of family," says Kerstin Faltermeier. The mother of a 3-year-old son has worked in the field of Corporate Communications since 2009. "Here, an employee is a person and not simply a number. I know from personal experience that this isn't always the case, which is why I really appreciate the pleasant working environment." She has no hesitation in mentioning the company's own day care center "Villa Kunterbunt" as well as the flexible working hours and the option of working from home as further benefits of working for MR.

Alexander Koller feels that MR has recognized the signs of the times. "It is very important to get an idea of employees' opinions and to pick up on their suggestions," says the 43-year-old group leader. Koller came to MR as an apprentice in 1987. He later gained experience in other companies before returning in 2009. He is particularly pleased that MR has never cast doubt over Germany as a production location. For this to remain the case, he believes constant change is vital, even if it is not always easy. Roan de Bock agrees. "Together, we are continuing to build on our reputation as a Great Place to Work. The journey is far from over."

The Columbia story: In 2011, following a successful pilot project, a utility active throughout South America replaces its old, conventional dehydrating breathers with 90 MESSKO® MTraB® dehydrating breathers. Transformers in the middle of the rain forest, not far from the Pacific coast. A mostly deserted area. Soldiers guard the remote transformer stations. Temperatures above 40 degrees Celsius and suffocating 90 percent humidity put the technology here to the test.

In this scenario, MESSKO® MTraB® dehydrating breathers make full use of their greatest strengths: as soon as the silica gel within is saturated with liquid, sensor-controlled heating units automatically regenerate its absorption power. Instead of the oil reservoirs typically used in conventional dehydrating breathers, stainless steel filters keep the air clear of insects and dirt particles. Extremely break-proof, temperature-stable Duran glass provides the devices with continuous, reliable protection. The positive outcome of this retrofitting project: previously necessary inspection and maintenance work is now a thing of the past, the customer reduces its operating costs significantly and soon after the project end, Messko receives follow-up orders of the MTraB® dehydrating breathers for Chile and Peru.

Now, switching our focus to Canada: a short time later, MESSKO® MTraB® helps transformers to breathe a little easier in the HVDC transmission transformer stations of a large energy provider based in Winnipeg. And this under enormous temperature fluctuations since in the prairie province of Manitoba, icy winters with five months of permafrost per year are followed by hot summers. Only about a million people inhabit this area that is approximately twice as large as Germany, and Winnipeg itself is one of the coldest cities in the world. This Messko customer provides these far-flung residents with power, which is generated primarily in hydroelectric and steam power plants as well as wind farms. Excess energy is sent to the US via high-voltage long-distance lines.

As part of a retrofitting program, the energy provider equips numerous HVDC transmission transformers with MESSKO® DB200D dehydrating breathers. Using special flanges, the MESSKO® MTraB®-"S-class" connects to any type of transformer. The built-in filter heating systems, which complement the existing silica gel heating system, automatically power up whenever the temperature falls rapidly. These systems prevent condensation from freezing at the transformer outlet and guarantee the continuous exchange of heated inside air with cold outside air. Both of these processes ensure fault-free operation of the transformer stations. The result is a lighthouse project for the Canadian market that has people far outside of Manitoba talking.

TECHNOLOGY: MESSKO® MTraB® Much of the time, conventional dehydrating breathers filled with common silica gel or similar desiccants are still used in transformers, on-load tap-changers and industrial processes. Depending on the application, their absorption power is typically exhausted within three to twelve months. Required periodic visual inspections and the regular replacement of used desiccants increase costs considerably.

The maintenance-free MTraB® dehydrating breather from MESSKO® provides the perfect solution to this problem. The silica gel in its drying chamber is dehydrated by an integrated heating element using sensor control. This minimizes visual checks and eliminates regular, costly desiccant replacement.

Since its market launch, the MTraB® dehydrating breather has been helping MESSKO® customers the world over to substantially reduce the life cycle costs of their transformers. It has set standards in the market and continues to do so today.



Etschwerke Netz AG was among the first to recognize how valuable this is. The largest utility company in South Tyrol supplies 33 municipalities with power in the thousand-square-meter basin of the megaregion Bolzano, Laives and Merano – 140,000 customers draw one billion kilowatt hours per year. In the transformer stations in Bolzano and Naturns, Etschwerke uses six transformers from various manufacturers in a voltage range of 220/66 kV.

To be able to monitor the transformers continuously and reliably based on data evaluated in detail, Etschwerke equipped them with ISM® and consolidated the data in the MR fleet monitoring system. ISM® is a field device which provides the defined data for each transformer. At Etschwerke Netz AG, the ISM® components were either fitted directly into the motor-drive unit, attached to the transformer in a separate housing or installed – decoupled from the transformer – in a control cabinet in the control room. In the new TAPMOTION® ED ISM® motor-drive unit, the intelligence is integrated ex works as standard.

Since then, ISM® has collected all data crucial for operation regarding effective, apparent and reactive power, gas-in-oil, moisture in oil, load current and load voltage, oil level and ambient temperature, tap-changer position and contact wear. Using an IEC transmission protocol, the data reaches a control center where TESSA® makes it visible in bundled form. "Prevention is crucial for us," says project supervisor Stefano Springhetti. "We want to be able to respond before alarms go off or damage occurs. To do this, we require all relevant information processed by intelligent software."

The software provides the asset manager with reliable results and recommended actions. This means lower maintenance costs, minimized risks and disruptions and simple and centralized service and resource scheduling. Various depictions in the TESSA® fleet monitoring system permit a quick check or a detailed review of individual equipment or the entire fleet, as required.

The analysis so far: implementation has progressed smoothly; handling and efficiency are convincing. One reason that the parties responsible at Etschwerke Netz AG have already started working on the expansion of the system.

TECHNOLOGY: TAPMOTION® ED ISM® AND TESSA® As a cost-effective and practice-oriented solution, the new intelligent TAPMOTION® ED ISM® tap-changer motor-drive unit makes asset management and operations management significantly easier. Its Integrated Smart Module ISM® completely monitors individual transformers and serves as a base for MR's innovative TESSA® fleet monitoring system.

All TAPMOTION® ED motor-drive units previously supplied by MR can be retrofitted easily and cost effectively with ISM® as a retrofit module. Of course, there is also the option to add ISM as an individual solution independent of the drive.

TESSA® relies on communication channels that are already in place, such as data lines or existing control systems. Visualization occurs via an integrated web server with ISM® interface without the user needing to install supplementary software packages.



For us, knowledge transfer is much more than a catchword, it is lived reality. Our apprentices, who are provided with the most exceptional technical support, know this just as well as employees affiliated with MR who continue to train and qualify themselves over many years. This can also be confirmed by the more than 14,000 participants from 170 countries who, since 1976, have learned more about on-load tap-changers and the related technology in the course of individually compiled training programs in Regensburg or at the other MR training centers worldwide, whether in German, English, French, Italian or Portuguese, and always with didactically experienced trainers at their side, who take time and thoroughly address questions.

The Regensburg training center occupies 700 square meters. This includes six training rooms, spacious work rooms, an area with control and monitoring systems, as well as a platform for practical work with on-load tap-changers. In addition to 115 tap changers in models from the last 65 years, in some cases equipped with motor-drive units, there are also 42 functioning models, 9 monitoring systems, 23 training models for automation and control and many MESSKO® products.

In the training center, participants are introduced to seven trainers who, taken together, have a total of 125 years of field experience as service technicians. They convey everything worth knowing about tap changers and their functions, in theory and practice, to transformer manufacturers. Operators of transformers can focus their training on the function and maintenance of tap changers and on monitoring.


Regensburg, Germany
Phone: +49 941 4090-7755
Fax: +49 941 4090-7701

Johannesburg, South Africa
Phone: +27 11 8352077
Fax: +27 11 8353806

São Paulo, Brazil
Phone: +55 11 4785-2150
Fax: +55 11 4785-2185

Kuala Lumpur, Malaysia
Phone: +60 3 2142-6481
Fax: +60 3 2142-6422

Suzhou, China
Phone: +86 21 61634588

Quebec, Canada
Phone: +1 514 3705377

Kingsgrove, Australia
Phone: +61 2 95022202

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10/08/2016 12/08/2016 desktopdefault.aspx/tabid-11/1113_read-467/date-442/ TVPPA Engineering & Operations Conference 2016 TC, TA/TM
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