Protection Class

Class I transformers
A transformer in which the protection against electric shock relies on the basic insulation but includes additional precautions, such as an earthing terminal for the connection of accessible conductive parts to the protective earthing conductor.

Class II transformers
A transformer in which the protection against electric shock relies on a double or reinforced insulation, there being no provision for protective earthing or reliance upon installation conditions.

Class III transformers
A transformer in which the protection against electric shock relies on supply at SELV, and in which voltages higher than those of SELV (50Vac) are not generated. There are no earthing terminals for the connection of accessible conductive parts to the protective earthing conductor.


Protection degree

Our transformers are built by default with a protection degree that can vary from IP00 to IP20, depending upon the construction.


Cooling

By default, our transformers are designed to be installed in environments cooled by natural air.
Upon request it is possible to build transformers for environments with no airflow or with forced ventilation.


Nominal power

Power in transformers is usually expressed in VA (apparent power). If the needed power value is expressed in Watt, it must be considered that the relation between the two numbers is based upon the cosφ (W = VA x cosφ). It is also important to consider the efficiency of the load, as it will affect the power output of the transformer.


Nominal frequency

Our transformers are designed by default to work with the nominal frequency of 50 Hz, however they can work correctly at 60Hz. Upon request they can be built specifically for the 60Hz frequency. We can also provide special constructions that can work with custom frequency values based on specific requests from the Client.


Insulation Thermal Class

The insulation Thermal Class determines the maximum temperature to which the insulating materials can be exposed without compromising their mechanical and electric characteristics. It is usually expressed in combination with the maximum ambient temperature for which the transformer is designed.
In the table below are reported the typical thermal classes used in transformer production:

Nominal power / ambient temperature ratio

Nominal power / altitude ratio

Standards reference

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