Quality and safety at the forefront

We check that all our transformers are compliant with the applicable regulation in the electrical field. Only the equipment which passes all tests obtains the check stamp. Our transformers are compliant with the EN 60076, EN 60989 and EN 61558 European standards for insulation transformers.

Prototype final testing

We check that the prototype perfectly meets the customer requirements. As well as the routine tests, prototype final testing involves additional tests thanks to which we can assess the transformer operation in the context of its actual use, measuring the noise, temperature and efficiency.


Designing and building customised products means offering the most appropriate solution for the customer needs, while respecting the regulations and laws in force. The parameters indicated on the products can be modified according to customer specific requirements.

  • temperature rise with the resistance variation method as envisaged by CEI EN 61558-1 legislation;
  • off-load leaks;
  • leaks in short-circuit;
  • efficiency control.

EMG® three-phase transformers are highly customisable which is why they can satisfy all customer needs. The three-phase transformers are fundamental components for example in UPS units, renewable energy production systems such as photovoltaic systems, and in the railway industry.

  • Voltage ratio
  • Off-load absorption current
  • Dielectric strenght
  • Insulation resistance
  • Induced test
  • Vector group
  • Winding resistance
  • Dimensions
  • measurement of sound pressure (in dB) under nominal and strain conditions (in other words with voltage values increased by 10-15% with respect to the nominal voltage);
  • calculation of sound power (in dB), as required by applicable legislation;
  • power supply through a converter with switching frequencies ranging from 1 to 10 kHz and with carrier frequencies ranging from 30 to 1,900 Hz variable in order to check temperature and noise;
  • on-load non-linear final test up to 100 kVA.

The EMG®  transformers and  autotransformers are tailored-made solutions, depending on technical requirements, uses, applicable rules and standards, as well as technical feasibility


Number of phases

Maximum nominal voltage 


Insulation class

Electrostatic screen


Protection level

Maximum room temperature


Compliant to regulations



from 100 VA to 1 MVA

  1 (singlephase) / 3 (three-phase)


  50 / 60 Hz, on request other frequency

  F /H

  on request or technical specifications

  cable terminals / bars, on request other connections

  IP00, on request other temperatures

  Ta = 40°C, on request other temperatures

 up to 1000m

EN 60989 - EN 60076 - EN 61558

on request or technical specifications

Static converters
Railway system
Automatic system
Emergency unit
Renewable energy




Insulation Voltage

Number of secundaries or primary

Vcc %

Vector group

Thermal sensor

Electrostatic screen



on request

Insulation class

Resin impregnated

Protection level

Maximum room temperature

Air cooling

Simulation test

on request or technical specification

  horizontal / vertical

  on request or technical specification

on request or technical specification

on request or technical specification

on request or technical specification

none / type PTC / NC thermal contact  

none / yes

Cable terminals

Copper / Aluminium bars

Termoplastic terminals

Customised screw terminal board

Weidmueller, Synflex, Phoenix clamps

Pre-wiring ending wires

F / H

no / yes

IP00, on request other IP (e.g. box)

Ta=40°C, or  on request

natural air / forced air

on request or technical specification

Not only EMG® products are highly customisable depending on application field in which they are used (railway industry, renewable energy production system, etc.), depending on the most various needings, thank to countless options for customization.

The use of resin impregnated transformers allows to have high insulation levels of 30 kV, hence passing the water immersion test. This type of transformer is used in environments with a high level of humidity, condensation or dust, which is typical of railway applications


Other products

Three-phase input and single-phase output, open delta connection. The open delta design means an imbalance between the three phases, equal to (IR+IT=IS). In order to reduce the imbalance of the input currents they can be built using three wound coils and an accessible primary neutral.

 Technical specifications and personalisations as three-phase transformer