The entire production is manufactured according to EU Regulation No 548/2014, Directive 2009/125/EC, and to European Standards CEI, IEC, CENELEC, DIN, BRITISH STANDARD, UNI EN, ISO

and more. Various are GBE S.p.A. recognitions and certifications such as RINA, DNV, Lloyd'S Register

and other naval and marine recognitions.

Magnetic cores are manufactured with cold rolled grain oriented magnetic sheet with high magnetic permeability and specific losses, isolated on both side by a slide of inorganic material (Carlyte). The individual 45° cut sheets are manually assembled into cores using the “Step Lap“ technique. Thus, especially good flux distribution at the joints is achieved resulting in exceptionally low losses and minimal no-load noise level. The clawing is obtained with zinc frame core which are dimensioned in the best way to guarantee strength and static nature for all the movements during transportation and discharge, electric dynamic strain and the most difficult installations. The primary and secondary windings are made with electrolytic aluminum or copper, with insulation in pure cellulose paper or double enameled for wires of small diameter. These windings are oval or circular section and are a concentric type, coaxial to the core columns. The high voltage winding is made with a wire or a metal strip, helically wound with more layers or with continuous disc in relationship to the working voltage and the transformer's power. The low voltage windings are made with foil or strip and are equipped with terminal bars welded along the whole coil length in order to guarantee the correct sturdiness and electro-mechanical stress. Each winding layer of low and medium voltage is insulated with pure cellulose paper, the oil circulation and necessary cooling are assured by wide channels placed between the windings layers. Insulation between high and low voltage and between the latter and the core is made with compressed cardboard cylinders with a well-sized thickness.

The adjustment or variation of the primary voltage is obtained by oil immersed linear tap changers maneuverable with the transformer disconnected from the network by using knobs placed on the cover. To avoid an incorrect positioning of the tap-changers, holes are provided in correspondence with each indication notch. Thus, the secure housing of the knob is guaranteed in each of the various positions. If required, the transformer may also be equipped with linear and compact on-load tap changer (for Voltage Optimization Local Transformers) or traditional types with oil-contacts or vacuum contacts, which regulate the voltage variation on energized transformers. GBE S.p.A. offers transformers equipped with any make of on-load tap changer in the market also for small power range.

The filling of the transformers is obtained with mineral oil, without PBC, dried and degassed, with electrical and chemical specifications, which conform to the CEI and IEC standards; the filling is done under-vacuum for the best oil electrical rigidity withstand. If required the tank can be filled with silicon type dielectric oil, MIDEL® or FR3