Othonos 39, 17343
Agios Dimitrios Athens
09:00 - 17:00


Ministab (1-120 KVA)(1:1/3:3)

Electrodynamic Voltage Stabilisers 

IREM Ministab voltage stabilizers are electromechanical devices with electronic control designed to ensure stabilized powering to single-phase and three-phase loads of small and medium powers. OPERATION: IREM Ministab voltage stabilizer is equipped with a control circuit that constantly monitors the line voltage at true voltage (RMS) and compares it with the pre-set voltage value to be kept constant. The architecture of IREM Ministab voltage stabilizer allows to achieve high values   of regulation speed and stabilization accuracy. The choice of adopting the booster configuration for the entire range, avoids the presence of mobile contacts in series to the line, makes the equipment insensitive to the load power factor, prevents the introduction of harmonic distortions and allows to achieve high efficiency levels, resulting in reduced heat dissipation and minimization of operating costs in relation to the benefits obtained.


  • Multi range: one model meets 4 levels of compensation and power
  • Toroidal variable autotransformer
  • Power range: from 1 to 350 KVA
  • Compact dimensions: “case” for single-phase M and threephase T models, “tower” for three-phase Y models.
  • Warranty: 5 years
  • Natural convection: fan-free for IP21 versions.
  • Heavy duty power: the declared performance is always ensured in the most severe and critical conditions (continuous service at nominal power with minimum input voltage, highest input current and at the declared ambient temperature).


Product Brochure


This is the distinctive characteristic of all IREM voltage stabilisers with protection degree IP21; it dramatically increases the reliability as the cooling of the magnetic components and the electronic control boards is ensured by natural convection without fans (fan free system). Fans and the relevant filters must be constantly checked, cleaned and periodically replaced. Moreover, the absence of fans avoids sucking of dust which would deposit on the copper tracks reducing the contact surface between the electro-graphite rolls and the voltage transformer tracks. As a consequence, this would cause roughness, sparks and copper smelting, phenomena that in the long run would damage the component and reduce its life expectancy. The pictures clearly show that NO fan is used in IREM voltage variable transformers to cool down the contact point between brushes and turns. This is possible thanks to the thermal dissipation being the result of:

  • the correct sizing and the high permeability of the magnetic cores;
  • the low density of current flowing through the windings of the variable transformers, and consequently the reduced thermal dissipation;
  • the square section of the linear variable transformers.


The fundamental parameter of a voltage stabiliser is the nominal power expressed in kVA and indicated in the product name plate. It represents the maximum power that the equipment can deliver. However, the power of a voltage stabilizer must be contextualized with reference to the service class, to the input voltage fluctuations and to the ambient temperature.


All IREM voltage stabilizers are designed and manufactured to operate in continuous service, intended as the most demanding service at nominal power for unlimited time. In other words: IREM voltage stabilizers are sized to work continuously with 100% duty-cycle and the materials used bear the maximum power expected for unlimited time.


A voltage stabilizer is characterized by the ability to compensate for the fluctuations in the mains voltage and to supply the connected load at a constant voltage and close to the nominal value. The most heavy working condition is in presence of the minimum mains voltage in input. All IREM voltage stabilizers are characterized by the ability to stabilize the output voltage when the mains is in the worst conditions for unlimited time and without any degradation of performance.


Electric machines are characterized by energy losses produced during energy transformation, which occur in the form of heat. The cooling of an electric machine occurs through the phenomenon of transmission of the heat produced inside the equipment to an element at a lower temperature. The most reliable cooling mechanism is when the machine is immersed in the air, at the ambient temperature, without forced ventilation elements (fan-free). The fan-free natural air convection cooling system typical of IREM voltage stabilizers in IP21 version requires that the energy losses are reduced to the minimum value allowed by the technology, using qualified materials and adopting a generous sizing criterion.


Extended warranty to 5 years.


In the voltage stabilisers with IP21 protection degree, cooling is ensured by natural convection only. The total absence of fans (fan-free) increases the reliability of the product dramatically and makes the use of filters, which would need constant maintenance, unnecessary.


The criteria used to size the electrical and electronic parts of all IREM voltage stabilisers guarantee the greatest reliability. The declared performance is always ensured in the most several and critical conditions for unlimited time (heavy duty): nominal power with minimum input voltage, highest input current and at the declared ambient temperature.


IREM voltage stabilisers are characterized by long life, no degradation of performance over the time and reduced maintenance requirements, thanks to the robustness of construction and the high quality of the materials used. They are characterized by a reliability (MTBF) of more than 500,000 hours.


Single-phase and three-phase voltage stabilisers from 1 kVA up to 8000 kVA. Voltage range from 110V to 500V. All the voltage stabilisers are available in symmetrical configuration ±10%, ±15%, ±20%, ±25%, ±30% and in asymmetrical configuration -35% +15%. Different configurations are available on request.


The whole range of voltage stabilisers has a very high level of customization, both in terms of electrical characteristics as well as mechanical and aesthetic. A staff of technicians specially dedicated to “special” projects can satisfy the most demanding request


  • Attenuation of voltage spikes
  • Short circuit protection
  • Overload protection
  • Over/under voltage protection
  • Reversed phase sequence / phase failure protection
  • Over temperature protection
  • Soft start
  • Functional by-pass
  • Maintenance by-pass
  • Galvanic separation
  • Neutral-point reactor
  • Input/output adapting transformer
  • Attenuation of common mode and transverse mode noise
  • Harmonic filter
  • Smart management of the plant
  • Modular system from y326
  • Remote control
  • Storage of electrical, physical and alarm status parameters