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Our customers
NFO Sinus in all environments.


Completely interference free environment

NFO Sinus can guarantee a completely interference-free environment,” says Tord Ringenhall, Product Manager at DeLaval International.

DeLaval develops, manufactures and distributes equipment and complete systems for milk production and animal husbandry. The company’s strategy is to offer its customers modern and energy efficient products.

A long-term collaboration agreement has been signed with the Swedish company NFO Drives. The agreement concerns annual deliveries of the interference free NFO Sinus frequency inverter, which will be used to control the speed of electric motors in DeLaval’s own products, including milk pumps and vacuum pumps.

“Cows are sensitive to earth leakage currents and stables and their surroundings also contains technical equipment that is sensitive to electromagnetic interference” says Tord Ringenhall.

“We have tested the NFO inverter for a long time in both laboratory and stable environments in farms around the world and know that it doesn’t cause any electromagnetic interference and neither earth leakage currents nor ball bearing currents. NFO Sinus is therefore entirely suited to DeLaval’s product strategy.”

“We are now using the NFO inverter to control our vacuum pumps but see a range of other applications where we can benefit from the interference free technology,” says Tord Ringenhall.

World leading

DeLaval, a company in the Tetra Laval group, is active in over 100 markets and supplies to customers with livestock herds from 1 to 50,000 animals. Milking equipment is a central product, and machines are available in many different versions from the simplest manual standard machine to advanced automatic milking systems and “cow carousels”.

DeLaval worker

DeLaval AMRTM is a revolving voluntary milking system with a capacity of 800 cows twice per day.

DeLaval NFO Sinus

DeLaval NFO Drive, which is used to control DeLaval’s vacuum pumps, is an OEM version of the NFO Sinus frequency inverter and is completely free from electromagnetic interference, earth leakage currents and ball bearing currents.


"NFO Sinus is the first inverter approved for naval vessels,” states Karl-Axel Olsson, who is Manager of Electrical Systems at Saab Kockums in Karlskrona.

“Following extensive testing, both in the lab and at sea, we have now approved NFO Sinus for use in our naval vessels,” reports Karl-Axel Olsson. “This is the first frequency inverter to have been approved.”

Kockums is part of the Saab Group and one of the world’s leading shipyards. The Karlskrona shipyard produces submarines and surface vessels for the Navy, specialising in stealth technology. The vessels have a great deal of advanced technology, which is sensitive to EMC interference. All equipment must therefore be meticulously tested.

One element of risk for the vessels is that in combat or terrorist attacks they may be exposed to dangerous gases, e.g. chlorine or nerve gas. Even in times of peace, gases constitute a risk in the event of fire or accidents in port. To prevent gases penetrating the vessels, overpressure must be created in the cabin. This is done by controlling the speed of the motors in the ventilation system.

“We have not previously been able to use frequency inverters at all,” states Karl-Axel Olsson “All inverters interfered with the sensitive equipment on board and were therefore banned within the Navy.”


“Through market research we got to know about the NFO Sinus frequency inverter. We tested it in our own EMC lab and were impressed with the results. We have also carried out extensive tests at sea. NFO Sinus fulfils all our requirements for interference-free motor control at a very moderate price.”

Fulfils all our requirements for interference free motor control at a very moderate price


The electrical systems in health care must be clean. We need to save energy without risking problems with our medical equipment,” says P-O Eliasson, Electrical Systems Developing Manager at Östergötland County Council.

“If you install a conventional PWM-type inverter, you notice it on the network immediately. The earth leakage currents exceed the limits of the earth current monitoring, which have to be raised for equipment to work. That is not acceptable.

“We also avoid the irritating howling motor sound PWM inverters emit. NFO Sinus are both quieter and more reliable.

In Östergötland  County Council there are several big hospitals: Linköping University Hospital,  Norrköping and Motala Hospital as well as a big number of Health Care Centers, Dental Care Centers and Nursing Homes.


P-O Eliasson, Electrical Systems Developing Manager at Östergötland County Council .

Patient safety is paramount, which is why we have chosen NFO Sinus inverters for all our hospitals and care centres at the County Council. They don’t generate any earth leakage currents, so we avoid all interference problems.

Landstingt Östergötland


Patient safety is paramount


"The frequency inverters now allow us to control the fans to adapt the air flow to our requirements,” says Malte Enocson, property manager at ICA Fastigheter. “The result is a much more pleasant and much quieter environment”.

ICA’s cold storage warehouse in Långeberga is counted as one of the most modern in Europe. 

“By choosing the NFO Sinus frequency inverter, we have been able to make use of the existing unshielded fan motor cabling as well as place the inverters far away from the motors, just as we wanted,” says Malte Enocson,

property manager at ICA Fastigheter. “The installation was fast and simple, and the inverters are now installed in the electrical distribution box easy for service staff to access.”

ICA’s largest cold storage warehouse, almost 70,000 square metres in size, is located in Långeberga outside Helsingborg. The warehouse, commissioned in 2006, is counted as one of Europe’s most modern FMCG facilities. A huge flow of goods takes place on a daily basis through the 141 doors to supply some 700 ICA shops with frozen products.
At its highest point, it is 15 metres to the warehouse ceiling. A large number of fan units distribute the cold air to constantly maintain a steady temperature of around minus 26°C throughout the entire warehouse.


“Initially we had a lot of problems with noise, draughts and wind gusts from the fan unit and decided as a result to frequency control the fans, partly to improve the working environment but also to save energy,” says Malte Enocson, property manager at ICA Fastigheter.

“Frequency inverters allow us to control the fans so that the air flow is adapted to our requirements. It results in a quieter and more pleasant environment. It was possible to install all the NFO inverters in the adjoining technology building with the other electrical/control equipment used for cold storage, which is much appreciated by our operational staff.

ICA Fastigheter NFO Drives

Malte Enocson

Property manager ICA

ICA - NFO Drives

ICA’s largest cold storage warehouse, almost 70,000 square metres in size.

ICA - NFO Drives
ICA NFO Drives

It is 15 metres up to the ceiling where the fan unit is installed in the cold storage warehouse.

Solution for better environment in ICA’s cold storage facilities

LKE Lasershowteknik

Safer pump control with residual current device

Using the interference-free NFO technology, the German company LKE LasershowTechnik have better control of their water pumps. Conventional frequency inverters were previously used but there was a problem with the residual current devices always triggering. There are no disruptions with NFO Sinus frequency inverters and the facility is significantly safer.

LKE has extensive experience in using frequency inverters in its facilities erected around the world – such as mobile facilities for major events like anniversary celebrations and sporting events and stationary facilities at amusement parks, etc.

The frequency inverters are used outdoors to control pumps which shoot water cascades to different heights according to a defined program. Each pump is controlled by a frequency inverter and different sizes from 1.5 kW up to 15 kW are used.

The water is lit up with lasers to create different effects and images are projected onto the water cascades. Together they create a spectacular display that is visible to an entire town or park and usually draws large crowds. For safety reasons, residual current devices are required for this type of facility.

“We used conventional PWM inverters before, but then we had extensive problems with the residual current devices always triggering due to earth currents maxing out,” says Matthias Kestler from LKE. “When the show kicked off, it just went swoosh like a pinball machine when all the residual current devices were set off.” We had to have a person on hand just to run around and reset them.

“Now we have used NFO Sinus for some time and are impressed with the technology,” says Matthias Kestler. “With NFO inverters, there are no problems with earth currents and our facility is safer.”

NFO Drives LKE
NFO Drives LKE

All water pumps are controlled by NFO Sinus frequency inverter. As it is interference free RCDs can be used our facility is safer.

Nicotra Gebhardt

NFO Sinus sets completely new limits for what a frequency inverter can manage

Ventilation, these days, is considerably more than just a fan which turns. It is a question of requirement adaptation – tailor-made solutions with controlled air flows. Solutions which give tenants in apartment blocks maximum comfort, irrespective of the time of year, says Basse Malmqvist at Nicotra Gebhardt.

New, more stringent demands, have thus meant that many old, belt driven fans in apartment blocks have now been replaced by modern, direct driven

fans with speed control. Nicotra Gebhardt, which has its main market in residential property, is currently working flat out on these conversions.

”But it has not been entirely without problems. Speed control with conventional frequency inverters generates interference and thus requires filters and shielded motor cables. In old buildings, this means extensive and expensive installations.

These days, we can supplement these fans with NFO Sinus – a new technology which sets completely new limits for what a frequency inverter can manage. NFO Sinus guarantees freedom from interference. Freedom from interference which means un-shielded cables and no radio interference filters. The fan is changed and the NFO Sinus can be connected to the existing cable. This is unique.

But there is also another important aspect: What we call frequency noise. The noise which is generated in the motor during all conventional frequency control. This problem is not found at all when we use NFO Sinus. Quiet fans, quite frequency inverters and quiet motors – NFO Sinus is completely in line with our mission.”

Nicotra Gebhardt

NFO Sinus sets completely new limits for what a frequency inverter can manage.

British Antarctiv Survey

Interference free in Antarctica

"No interference was detected from the NFO Sinus  inverter.” After careful testing, BAS (British Antarctic Survey) has decided to use the Swedish frequency inverters NFO Sinus for the new climate research station Halley VI in Antarctica.

The inverters is used to control the fan motors in the ventilation system, and thus create a good indoor climate in the extreme Antarctic environment. As the station will contain a large number of advanced technical measuring instruments, the absence of electromagnetic

interference on the measurement equipment is essential.

NFO Sinus was tested by BAS at the present research station in Antarctica. The result of the test was reported in the “AIS Fuel Pump Inverter Interference Report” by Julius Rix, Electronic Field Engineer at BAS. In contrast to the results from other inverters tested, no interference from the NFO Sinus®inverter was detected by the AIS (Advanced Ionospheric Sounder).

Another important factor in the choice of inverter was high operating reliability, as the research station has no contact with the outside world for several months each year.

Great Britain has been carrying out climate research at the South Pole for over 50 years through the British Antarctic Survey (BAS), an institute within the Natural Environment Research Council.

British Antarctiv Survey
British Antarctiv Survey

The new climate research station Halley VI in Antarctica

Oslo sjukhus NFO Drives

The interference-free frequency inverters exceeded our expectations

The new University Hospital in Oslo was built in 1997 and was Norway’s largest construction project at that time. The hospital is equipped with over 500 motor drives to enable air and water supplies to be adjusted as required. This saves huge amounts of energy.

​The hospital decided to use conventional PWM (pulse-width-modulated) frequency inverters for a start. Johnson Control Norden AS has been responsible for this part of the ventilation system at the University Hospital. Engineer Martin Olsen states:

“At Oslo University Hospital HF, the National Hospital, we have replaced more than 300 conventional PWM-type inverters with interference-free NFO Sinus® ones,” says Martin Olsen, who is in charge of the service contract at the Oslo University Hospital for Johnson Controls.

“Since we switched over, we have had none of the problems involved with PWM inverters. The motors run quieter and there are no earth leakage currents.”

“The bearing damage problems PWM inverters caused have also disappeared. Having to replace bearings several times a year is hardly financially viable when you have 600 motors in your system.”

NFO Sinus is the only frequency inverter on the market that comply with the “Medical Device Directive” for electromagnetic interference.

NFO Drives Oslo

“We have replaced more than 300 conventional PWM-type inverters with interference-free NFO Sinus® ones,” says Martin Olsen.

Chalmers NFO Drives

The  installationen of NFO was both easier and cheaper

“NFO Sinus® solved the operating problems in our Nanotech Laboratory and we now have obtained both operating safety and a quiet system”, says Christer Andersson, Research Engineer at Chalmers Nanotech Laboratory in Gothenburg.

At first our pumps were directly connected to the mains and the water flow was controlled by induction taps. This meant that the pumps had to work at maximum power and were therefore exposed to too much wear. There was a harsh force in the water system on start up and stop, which broke the flow indicators. To solve the problem we searched for a suitable frequency inverter with a soft start.

As our entire ventilation system is equipped with conventional frequency converters, we were aware that these caused real problems as regards noise, electrical disturbance and bearing damage to the engines,” continues Christer Andersson.

“We found NFO Sinus®, which is a new type of frequency inverter that creates a sine wave output voltage. This allows us to achieve the perfect soft start and correct pump frequencies without other operating problems arising so, it ensures both operating safety and a quiet system. Another advantage of this new technology is the electrical installation, which is much simpler and cheaper, as we don’t need shielded cables and are not limited by cable lengths.”

“From a purely financial viewpoint, saving electricity is a very important factor in addition to achieving a longer lifetime for the pumps. If we can control all of the fan motors and pumps with the frequency inverter, we will save a great deal of electricity. We estimate that the installation will pay for itself within 1-2 years,” concludes Christer Andersson.

Chalmers NFO Drives

Chalmers Nanotech Laboratory at the Institute for Microtechnology and Nanoscience – MC2 – contains super clean rooms where very high standards for moisture, temperature and air purity are required. For everything to be as environmentally friendly as possible, all emissions must be checked and energy consumption must be optimized.Scrubbers are used to clean the air of the chemicals in the drawbenches.

Air is driven through a zone in the scrubbers that contains showerheads. The water is treated to stop harmful substances entering the environment.

Karlskrona Water Works

Reduced the energy consumption of the pumps by over 50%

By installing NFO Sinus we can reduce the energy consumption of the pumps by over 50 %,” says Anders Nilsson, who is leading the electrical installation project at the municipality’s water and sewage works at Karlskrona.

Karlskrona Municipality has conducted several energy saving projects in the municipality’s water, sewage and cleaning works, where pumps in the raw water wells are controlled by NFO Sinus®frequency inverters.

“The installations will rapidly pay for themselves, often between one and two years, continues Anders Nilsson. “NFO Sinus was the only inverter that could cope with the technical conditions in our applications.”

“Groundwater is collected into our network via raw water wells. These pumps are often located at a depth of 50 metres or more, and the distance to the circuit panel is several hundred metres in some cases.

As the NFO inverters can be installed in unshielded cabling and can also handle long cable Distances, we can use the existing cabling. We therefore avoided the difficulty and expense of laying more than 250 m shielded cabling, which would have been the case if we had chosen conventional inverters.

In addition, the signal cable to the sensors could remain together with the power cable at the bottom of the well without any interference to the surrounding electronic apparatus.”

“Previously we ran the pumps by an engine drive, which was choked with a manual valve. This consumed far too much energy. We had problems controlling the pumps in the optimum way and also risked them dry pumping. We were forced to drive out to the raw water well to change the setting manually – now we can take care of everything centrally.”

“Being able to situate the NFO inverters in the circuit panel several hundred metres from the pumps has been a major advantage in our purification work. This is a very aggressive environment due to the hydrogen sulphide in the air, however we can now situate the inverters in a considerably “nicer” environment.

Karlsrkona NFO Drives

- NFO Sinus was the only inverter that could be installed in this way, säger Gunnar Pettersson, Manager of the Electrical department.

Karlsrkona NFO Drives

- The location of inverters in the circuit panel, several hundred metres from the water pumps, was a major advantage, says Anders Nilsson, Project leader

Karlsrkona NFO Drives

“We avoided the difficulty and expense of laying more than 250 m shielded cabling which resulted in a short pay-off time,” says Anders Nilsson.

Jönköping NFO Drives

Completely interference free operation at a considerably lower overall cost

— NFO Sinus® inverter was a little bit more expensive but, as installation was considerably simpler, it resulted in a lower overall cost, says Mikael Falk, Chief Engineer for the university properties.

–The Jönköping University mainly consists of newly built properties. However the School of Health Sciences is a little older and some old industrial properties, which have been integrated into the area, have been transformed into a modern library.

“When the new School was built we wanted to use frequency inverters to control the motors for all fans and pumps to be able to save energy”, says Mikael Falk. “However it was important for us to achieve an interference free solution as we have a great deal of technical equipment and also a large amount of wireless communication within the area.”

“We wanted to find a solution that would avoid expensive shielded cables in our premises,” continues Mikael Falk. “Then we found the Swedish NFO Sinus®inverter. It was completely interference free and didn’t require any filters or shielded cables, unlike conventional inverters, and our standard cables could be used. The inverter was a little more expensive but, as installation was considerably simpler, it resulted in a lower overall cost.

There was a particular advantage to using NFO Sinus®in the older properties. There we could avoid laying new cables and just used the existing ones when we installed the new inverters. This allowed us to save a lot of money.”

“One common problem with conventional PWM inverters is that they produce bearing currents, which can cause break down in ball bearings. We have several such inverters for motors with powers exceeding 15 kW, which today is the maximum for NFO Sinus®. However even though we have equalized the potential of all the properties, we have still had certain problems with these PWM inverters.”

“We have experienced no such problems with NFO Sinus®,” says Mikael Falk, “and now, after five years in operation, the NFO Sinus® inverters still have a perfect function.”

Jönköping NFO Drives
Jönköping NFO Drives

Jönköping University. All properties are owned by Högskolefastigheter i Jönköping AB.


Lower installation costs and more reliable operation

We achieved lower installation costs and more reliable operation – and a quiet environment, says Göran Pettersson Electrical Manager at Trioplast in Smålandsstenar. 

“When the new refrigerating equipment was to be installed at Norra Fabriken it was only natural for us to choose NFO Sinus frequency inverters, as we had had good experiences with these in several earlier installations,” explains Göran Pettersson. “The refrigerating equipment was to be located on the roof, but we wanted to fit the frequency inverters controlling the motors in the control cabinet of the central refrigerating unit.

“If we had chosen a conventional type of inverter, we would have had to lay shielded cables from the control cabinet right up to the roof,” says Göran Pettersson. “As it was, we were able to use ordinary standard cables, and we didn’t need any interference filters either. This allowed us to substantially reduce the installation costs, while gaining a completely interference-free facility.” 

NFO Sinus is used in several locations at the factory. “We previously had problems with the suction fans on the roof,” continues Göran Pettersson. “The old motors there had integrated conventional PWM-type inverters of a well-known make, but the motors got too hot and we experienced constant stoppages.

Switching to NFO Sinus allowed us to site the inverters in the control cabinet, where the temperature is significantly lower. The existing cabling could be used, thus avoiding re-laying of the very troublesome cable run. Since the replacement, wear to the motors’ bearings has reduced, as bearing currents no longer occur. Operational reliability has improved considerably and everything now functions smoothly.

“In addition, the facility is quieter. By law, we are obliged to keep the noise emission below 45 dB at night. However, this was difficult with the old inverters, and the neighbours complained of the piercing noise from our premises. Since the switch to NFO Sinus, we can comply with these requirements and our neighbours are happy.”


Trioplast i Smålandsstenar has around 400 employees and manufactures stretch film, which is used for silage bales in agriculture, among other things. The company is part of the Trioplast Industrier Group, which is Sweden’s largest polyethylene company, with a turnover of more than SEK 3.3 billion


Karlskrona Navy Base

Interference free inverters was the solution

“Now we can save energy, and at the same time our radio transmissions work perfectly”

The Karlskrona Navy Base Radio School trains people to transmit and receive using various types of radio technology. As part of the total renovation of the school premises about two years ago, it was decided to improve the energy efficiency of the ventilation system and to install frequency inverters to control the fan motors.

“From earlier experience, I knew that all radio equipment is susceptible to EMC interference”, says Mats Lundbergs, Systems Manager at the National .

Navy Base

Fortifications Administration in Karlskrona. “It is difficult to get a totally interference-free environment with conventional frequency inverters – even using filters and shielded cables according to the manufacturer’s instructions

We were looking for a solution to achieve a low-energy ventilation system in an interference-free environment. We decided to test the NFO Sinus inverters which should meet our needs. These use a totally different technique and give an output voltage in the form of pure sine wave. This means that they do not need filters or shielded cables to be interference-free!

“At first we installed an inverter on trial and were able to establish that our radio transmissions were totally free from problems. We then decided that all inverters in the building should be of the same type, and in total nine inverters were installed. Now the ventilation system has been fully operational for some time and functions totally interference-free”, confirms a satisfied Mats Lundbergs.

“NFO Sinus has also solved other inverter problems here. We have a clothing change store area where we were forced to install a separate ventilation system to prevent people suffering from allergy problems. First a conventional inverter was used to control the fans. But a loud howling noise came from the fans. The sound caused by the frequency inverters was so disruptive that we could not have the fans running, says Mats Lundbergs. “So we tried changing to NFO Sinus. The unwanted noise disappeared immediately and we got a totally silent ventilation system.

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