Product Catalogue

Before consulting the catalogue we recommend referring to the SELECTION CRITERIA and reading the indications below.

GENERAL INFORMATION AND DEFINITION

ISOLATED TRANSFORMER
Transformer in which the primary and secondary windings are separated electrically by a double orreinforced insulation to limit, in the circuit powered by the secondary winding, risks caused by accidental simultaneous contacts with the earth and active parts or mass which can conduct in the case of a fault in the fundamental insulation.
N.B. The double or reinforced insulation must resist to an applied voltage of 3750 Volts for nominal voltages below 450V.

SAFETY TRANSFORMER
Isolated transformer for powering low tension safety circuits (< 50V without load). The accidental contact of the two phases on the secondary winding can be supported without any danger for man.The insulation class of a transformer is defined on the basis of the protection against direct and indirect contacts (the classification doesn't refer to the insulation system between the primary and secondary windings).

VOLTAGE DROP FROM UNLOADED TO LOADED
A voltage drop (∆V) is the difference in the voltage at the terminals of the transformer when passing from unloaded to loaded.

The international norm is to identify this voltage drop with the percentage value referred to the secondary nominal voltage:

∆V = (V₂₀-V₂)/V₂₀ x 100

Where: V₂₀ = Output voltage without load
Where: V₂= Output voltage under load

NOMINAL FREQUENCY
PAT transformers are designed to work at a nominal frequency of 50Hz, but they can also work at 60Hz.

ELECTROSTATIC SCREEN
The use of transformers to power sophisticated (electronic and computer) equipment and applications in medical environments, require the presence of an electrostatic screen between the primary and secondary.
The electrostatic screen, consisting of an open and insulated metallic spiral, earths the disturbances on the primary network (parasitic currents) so they cannot pass to the secondary circuit (user).
PAT transformers for use in medical environments are realised with this protection.

IMPREGNATION AND TROPICALIZATION OF PAT TRANSFORMERS
PAT transformers are fully impregnated using a class F polyester resin.
This operation gives the transformers the following characteristics:
· improved characteristics of the insulation used;
· improved heat exchange with the consequent reduction of the transformer's temperature;
· stops the penetration of humidity in the winding and in the core;
· improved mechanical characteristics of the windings;
· reduced noise caused by vibrations.
This particular productive process makes the PAT transformers suitable for installation in tropical environments, with a max:
. temperature of 40-50°C and a max
. relative humidity of 60-70% in continuous service.
On request we can realise transformers suitable for even more demanding conditions.

STANDARDS OBSERVED
The CE mark on the plate of all PAT products, indicates that they are conform to standards:
· EN 61558 for all the series of single-phase and three-phase transformers, both isolation and safety
· EN 61558-2-13 for all the three-phase autotransformers
· EEC 89/336-EMC (electromagnetic compatibility)
· EEC 73/23-Low tension directive