Dual-voltage transformer with coordinated fusing

Claim 2

Electrical inductive apparatus comprising a winding assembly having first and second voltage ratings, first, second, third and fourth protective means, first and second line terminals, electrical switching means having first and second positions, said switching means connecting said winding assembly to said line terminals through said first, second and third protective means to provide the first voltage rating when the switching means is in the first position, and said switching means connecting said winding assembly to said line terminals through said first, second and fourth protective means to provide the second voltage rating when the swtiching means is in the second position.

Claim 3

The electrical inductive apparatus of claim 1 wherein the first and fourth protective means are constructed to interrupt current flowing therethrough at a first predetermined value, the second and third protective means are constructed to interrupt current flowing therethrough at a second predetermined value, the first predetermined value being higher than the second predetermined value.

Claim 4

The electrical inductive apparatus of claim 1 wherein the winding assembly includes a first winding section, a tapped second winding section having first and second winding portions, the switching means connects the first winding section and the first portion of the second winding section in parallel circuit relationship with each other and in series circuit relationship with the second portion of the second winding section when the switching means is in the second position, and the switching means connects the first winding section and the first and second winding portions of the second winding section in series circuit relationship when the switching means is in the first position.

Claim 5

The electrical inductive apparatus of claim 2 wherein the winding assembly includes a first winding section and a tapped second winding section having first and second winding portions, the switching means connects the winding assembly and the protective means together when the switching means is in its second position to provide a line current path wherein the total line current flows through the first and fourth protective means and through the second portion of the second winding section, and substantially one-half of the total line current flows through the second protective means, the first portion of the second winding section, and the first winding section, and the switching means connects the winding assembly and the protective means together when the switching means is in its first position to provide a line current path wherein the total line current flows through the first, second and third protective means, the first and second portions of the second winding section, and the first winding section.

Claim 6

Electrical inductive apparatus comprising a first winding section having a first voltage rating with first and second end terminals, a tapped second winding section having third and fourth end terminals and an intermediate tap terminal, the voltage rating between the first and second end terminals and between the third and tap terminals of the winding sections being equal, first and second line terminals which conduct line current, first, second, third and fourth protective links each having first and second ends, said first and fourth protective links being constructed to interrupt current at a higher value than said second and third protective links, the first terminal of the first protective link being connected to the first line terminal, the second terminal Of the first protective link being connected to the first terminal of the second protective link, the first terminals of said third and fourth protective links being connected directly to each other and to the second line terminal, switching means having first and second positions, said switching means including a stator assembly with first, second, third, fourth, fifth, sixth, seventh, eighth and ninth stator contacts mounted thereon, a rotor assembly with first, second and third contact pairs mounted thereon, said first stator contact being connected to said tap terminal, said second stator contact being connected to said fourth end terminal and said fourth stator contact, said third stator contact being connected to said second end terminal, said fourth stator contact being connected to said fourth end terminal, said fifth stator contact being connected to said sixth stator contact, said sixth stator contact being connected to said third end terminal, said seventh stator contact being connected to the second end of said fourth protective link, said eighth stator contact being connected to the first end of said second protective link, said ninth stator contact being connected to the second end of said third protective link, said stator contacts and said rotor contact pairs being arranged to connect together appropriate contacts when the switching means is in its second position to provide a current path wherein the total line current flows through the first protective link and through the portion of the second winding section which is between the fourth end terminal and the tap terminal, and substantially one-half of the total line current flows through the second protective link, the portion of the second winding section which is between the third end terminal and the tap terminal, and the first winding section, the switching means connecting the winding sections and the protective links together when the switching means is in its first position to provide a line current path wherein the total line current flows through the first, second, and third protective links, the second winding section, and the first winding section.

Claim 7

Electrical inductive apparatus comprising a first winding section having a first voltage rating with first and second end terminals, a tapped second winding section having third and fourth end terminals and an intermediate tap terminal, the voltage rating between the first and second end terminals and between the third and tap terminals of the winding sections being equal, first and second line terminals which conduct line current, first, second, third and fourth protective links each having first and second ends, said first and fourth protective links being constructed to interrupt current at a higher value than said second and third protective links, the first terminal of the first protective link being connected to the first line terminal, the second terminal Of the first protective link being connected to the first terminal of the second protective link, the first terminals of said third and fourth protective links being connected directly to each other and to the second line terminal, switching means having first and second positions, said switching means including a stator assembly with first, second, third, fourth, fifth, sixth, seventh, eighth and ninth stator contacts mounted thereon, a rotor assembly with first, second and third contact pairs mounted thereon, said first stator contact being connected to said tap terminal, said second stator contact being connected to said fourth end terminal and said fourth stator contact, said third stator contact being connected to said second end terminal, said fourth stator contact being connected to said fourth end terminal, said fifth stator contact being connected to said sixth stator contact, said sixth stator contact being connected to said third end terminal, said seventh stator contact being connected to the second end of said fourth protective link, said eighth stator contact being connected to the first end of said second protective link, said ninth stator contact being connected to the second end of said third protective link, said stator contacts and said rotor contact pairs being arranged to connect together appropriate contacts when the switching means is in its second position to provide a current path wherein the total line current flows through the first protective link and through the portion of the second winding section which is between the fourth end terminal and the tap terminal, and substantially one-half of the total line current flows through the second protective link, the portion of the second winding section which is between the third end terminal and the tap terminal, and the first winding section, the switching means connecting the winding sections and the protective links together when the switching means is in its first position to provide a line current path wherein the total line current flows through the first, second, and third protective links, the second winding section, and the first winding section.