Abstract: A three-phase non-linear dry-type transformer has integral molds formed of a glass fiber-reinforced polymeric material. The low voltage coil is comprised of an inner low voltage mold formed around each of the at least three core legs, a low voltage conductor winding wound upon the inner low voltage mold and an outer low voltage mold formed around the low voltage winding. The high voltage coil is comprised of an inner high voltage mold disposed around the outer low voltage mold, a high voltage conductor winding wound upon the inner high voltage mold, and an outer high voltage mold formed around the high voltage conductor winding. An annular space between the inner and outer high voltage molds and the inner and outer low voltage molds is filled by an insulating polymeric material during a casting process. The molds are bonded to the coil windings by the insulating polymeric material and remain during the operation of the non-linear transformer as integral components of the non-linear transformer.

Abstract: A grounding switch is comprised of a structural frame, at least one first contact, at least one second contact, at least one spacer, and a geared drive assembly. The opening and closing of the grounding switch is controlled by the geared drive assembly. The geared drive assembly is operable to rotate the at least one second contact around the axis of a connecting rod to move the at least one second contact into and out of contact with the at least one first contact. The closing of the grounding switch first and second contacts serve to connect a transformer or other electrical device to ground potential.

Abstract: A three-phase non-linear transformer is cooled by first (30) and second fans (40). The first fan (30) is attached to the first core clamps (12) of the transformer using a first mounting structure (15). The second fan (40) is attached to the second core clamps (24) of the transformer using a second mounting structure (17). The first fan is positioned first so that air is directed toward a central passage of the core. The second fan is positioned so that air is drawn through the central passage of the core. The first fan circulates air through a central passage in the transformer core and channels that exist between adjacent coil assemblies. The second fan draws air through the central passage and channels and further expels the air into the surrounding environment. The first and second fans are controlled by a control panel through which they are run automatically or manually.

Abstract: A dry-type network transformer has a core and coil windings insulated by a combustion-inhibiting gas. The combustion-inhibiting gas, core and coil windings are disposed within a hermetically-sealed enclosure. The combustion-inhibiting gas is air, an inert gas or a mixture of gases. The dry-type network transformer may be connected to a network protector. The network protector is further connected to a secondary network. The network protector prevents power from flowing from a secondary network to the primary side of the transformer. The dry-type network transformer is installed in a vault that is underground or at ground level. The dry-type network transformer may be suspended near the ceiling of the vault or installed at the base of the vault.

Abstract: A three step non-linear transformer core is formed from three sections of laminations each having different widths and cross-sectional areas. A first section of laminations is formed by cross-slitting a generally rectangular sheet or strip of metal. A resulting generally triangular segment is then wound upon a mold to form a first section of a core frame having a trapezoidal cross section. A second section of laminations is wound upon the first section of laminations to form a segment of a core frame having a rhombic cross section. The third section of laminations is wound upon the second section of laminations to form a segment of a core frame having a trapezoidal cross section. Each of the first, second, and third sections of laminations are offset from one another by a predetermined angle of offset.

Abstract: A three step non-linear transformer core is formed from three sections of laminations each having different widths and cross-sectional areas. A first section of laminations is formed by cross-slitting a generally rectangular sheet or strip of metal. A resulting generally triangular segment is then wound upon a mold to form a first section of a core frame having a trapezoidal cross section. A second section of laminations is wound upon the first section of laminations to form a segment of a core frame having a rhombic cross section. The third section of laminations is wound upon the second section of laminations to form a segment of a core frame having a trapezoidal cross section. Each of the first, second, and third sections of laminations are offset from one another by a predetermined angle of offset.

Abstract: A composite electrical insulation material is comprised of first, second and third layers. The first and third layers are glass fiber mat and the second layer is a thin film material. The first and third layers are bonded to the second layer using a thin resin solution. The insulation is used in electrical machines such as transformers, generators, and motors. The insulation serves as a high/low barrier, high voltage conductor wrap, and low voltage sheet insulation in transformers. In generators and motors, the insulation serves as wrap for conductor windings and wedge insulation for stator and rotor assemblies.

Abstract: Tap covers and projections for an electrical device are provided. The tap projections have bosses or taps raised from a surface of the tap projection and encapsulated with a resin except for an outer surface of the bosses or taps. The tap projections may have a channel or recess between individual bosses or taps to prevent degradation of the insulation between the respective adjacent bosses or taps. When a tap cover is provided, it is pushed on or bolted to the tap projection. The tap cover may be provided for an individual tap or an entire tap projection and may be formed of a resin or an elastomeric material. The tap cover has a first generally planar surface and a second generally annular surface having a circumferentially-extending groove on an inside surface. The circumferentially-extending groove is located slightly beneath the second generally annular surface. The groove of the tap cover is designed to fully engage with a raised lip of a tap projection or individual tap of a transformer.

Abstract: A grounding switch is comprised of a structural frame, at least one first contact, at least one second contact, at least one spacer, and a geared drive assembly. The opening and closing of the grounding switch is controlled by the geared drive assembly. The geared drive assembly is operable to rotate the at least one second contact around the axis of a connecting rod to move the at least one second contact into and out of contact with the at least one first contact. The closing of the grounding switch first and second contacts serve to connect a transformer or other electrical device to ground potential.

Abstract: A dry-type network transformer has a core and coil windings insulated by a combustion-inhibiting gas. The combustion-inhibiting gas, core and coil windings are disposed within a hermetically-sealed enclosure. The combustion-inhibiting gas is air, an inert gas or a mixture of gases. The dry-type network transformer may be connected to a network protector. The network protector is further connected to a secondary network. The network protector prevents power from flowing from a secondary network to the primary side of the transformer. The dry-type network transformer is installed in a vault that is underground or at ground level. The dry-type network transformer may be suspended near the ceiling of the vault or installed at the base of the vault.

Abstract: A three-phase non-linear transformer and a method of constructing the same. The non-linear transformer includes a non-linear ferromagnetic core having a plurality of frames, each of which has a closed or substantially closed periphery. The frames are arranged to form at least three legs. A low voltage winding is formed around each leg and a high voltage winding is formed around each low voltage winding. Each high voltage winding includes a plurality of serially-connected disc windings. Each of the disc windings is formed of alternating concentric layers of a conductor strip and an insulation strip, wherein the conductor strip having a width to thickness ratio of greater than 10:1. A casing encapsulates each pair of high voltage and low voltage windings. The casing is formed using a mold at least partially formed by a winding device used to wind the high voltage and low voltage windings.