High-Voltage Technology

Application areas for electrostatic precipitators (ESP)


Our high voltage DC aggregates transform and rectify the primary end input AC voltage to the secondary end high voltage required for the operation of the electrical precipitator.

As we achieve this, we adjust not only to the wide range of global input voltages (380V, 400V, ...) and input frequencies (50Hz, .....), but also to the many different output voltages (70KV to 140KV). Our aggregates are designed to meet the specific requirements of each customer.High-voltage DC power units (Transformer rectifier).

The advantages of our high voltage DC aggregates at a glance

  • Maintenance free operation for many years warranted
  • Conservation of energy / reduction of CO2 through pulse operation possible
  • Specifically developed foil roll-up technology
  • Oil cooled electrical current restrictor
  • Silicium rectifier set
  • Interference and harmonic wave free filter voltage signal
  • Temperature, pressure and oil level monitoring with individual components
  • High frequency restrictor under oil
  • Minimal electrical losses
  • High thermal reserves
  • Insulation material boasts more than 200 kV per cm of di-electrical stability
  • Warranted not to contain PCB
  • CE labeled
  • Low noise set-up averts eddy currents
  • Sound output level pursuant to DIN VDE 0532 Part 7 Issue 1/92 < 65 dB (A)
  • Measuring resistances for voltage and current
  • Compact, weight-optimized design
  • Individual electrical filter connection options

Maintenance free operation for many years warranted

Our maintenance free high voltage DC aggregates are installed into a hermetically sealed oil tank without gas buffers. There is no need for an expansion vessel, which ensures that the transformer oil cannot absorb any humidity from the ambient air. Consequently, the oil does not age. As the oil is heated up during operation and expands its volume, it is caught by the elastic steel cooling fins. Our design warrants many years of absolutely maintenance free operation. It makes the use of cooling fans that require lots of maintenance, the cleaning of the filter mats, the taking of oil specimen or similar additional labor redundant.

Prior to delivery of any of our installations to customers, we test it under realistic conditions with sparkovers for at least 10 hours in our testing field. Our delivery package includes a complete test log as well as comprehensive documentation. As a result, you can rest assured that your installation will work without any malfunctions for many years to come.

Cnservation of energy / reduction of CO2 through pulse operation

Pulse operation is a standard feature of the design of all Rico machines. Pulse operation allows the user to cut down energy consumption and therefore related costs as well as the output of CO2 considerably.

Our transformer cores are designed for optimum pulse operation and can be run under the parameters you choose at your discretion.

Ask about all of the energy optimization options we offer, which can be aligned with the special properties of your electrical filter.

Specifically developed foil roll-up technology

We are the world’s only manufacturer of high voltage transformers that uses our in-house developed method of secondary foil roll-up technology. This method does not use the standard approach of winding up copper layer windings on top of each other, which can lead to temperature-related problems. Instead, we process aluminum foil into winding rings with extreme precision. This process optimizes the temperature distribution of the winding. Every layer of the winding is in contact with the coolant and can transfer heat losses directly to the coolant. Unlike cooper layer windings, these windings do not allow the development of areas where the heat is concentrated. An optimum amount of coolant streams through every layer. Even after decades of use, there is no charring of the insulation materials, given that temperatures in the winding never exceed the maximum coolant temperature. The excess voltage, which cannot be prevented in electrical filter operations, is distributed equally alongside the winding, thanks to the fact that our design ensures the equal distribution of the winding capacity.

Oil cooled electrical current restrictor 

The compact primary restrictor is designed for nominal short circuit currents and is oil cooled in the transformer tank.

Silicium rectifier set

Our proven silicium rectifiers are design for double idle peak voltage with a 5 ampere permanent current effective value.

Interference and harmonic wave free filter voltage signal

The construction and installation location of the high voltage separators is of critical importance for the interference free operation. The high voltage separators are designed in such a manner that an interference and harmonic wave free signal for the filter voltage is generated. The signal is picked up by a high-end Teflon coaxial cable in the aggregate already. This makes it absolutely impossible for the signals to be inaccurate.

Temperature, pressure and oil level monitoring 

Upon request, our high voltage aggregates can be equipped with temperature, pressure and oil level monitoring components. These highest quality individual monitoring devices are installed either into the transformer cover or into the terminal box, where they work reliably and without interruptions. Their long useful life is equal to that of the aggregate.

High frequency restrictor under oil 

The individually designed, high impact high frequency restrictor has the layout of an air-core coil and also features our foil roll up technology. It is located at the HS exit in the boiler under oil.

Conserving energy through pulse operation


Pulse operation allows the user to cut down energy consumption and to keep the output consistent. Each Rico high voltage aggregate can be pulse operated without any problems. Our transformer cores are designed for optimum pulse operation and can be run under the parameters you choose at your discretion. If you update your old installation to this standard, the investment will pay for itself after only a short period of time.


Individual connecting dimensions 

The external connections are designed based on your specifications and are consequently aligned with your filter design. We will obtain the following dimensions from you:

  • Flange dimensions
  • Height of the high voltage through-put
  • Is your high voltage feed-through horizontal or vertical?
  • Chassis dimensions and design
Cookies make it easier for us to provide you with our services. With the usage of our services you permit us to use cookies.
More information Ok