Abstract: An electrical transformer is disclosed. The electrical transformer comprises a central axis, a first modular section, and a second modular section. The first modular section is positioned about the central axis and comprises a first support, a first winding of a conductive element, and a first insulating material. The first winding of a conductive element is located about the first support. The first insulating material covers a portion of the first modular section. The second modular section is axially aligned with the first modular section and electrically connected to the first modular section. The second modular section comprises a second support, a second winding of a conductive element, and a second insulating material. The second winding of a conductive element is located about the second support. The second insulating material covers a portion of the second modular section.

Abstract: A two-stage gapped low voltage surge arrester for dissipating transformer secondary side current surges includes an arc strap in series with a resistive grommet. The combination is mounted on the grounded transformer housing adjacent a line potential bushing such that a first spark gap is formed between the bushing stud and arc strap. The resistive grommet is grounded to the transformer ground pad by metallic fasteners such that a second spark gap is formed in parallel with the resistive grommet. Surges entering the transformer secondary winding of sufficient magnitude induce the first spark gap to flash over, shunting potentially damaging currents outside the transformer through the arc strap and resistive grommet. At even higher currents, the voltage across the resistive grommet exceeds the flash over voltage of the second spark gap and shunts the surge around the resistive grommet.