Current transformer

An instrument transformer comprising:

• a circular magnetic core;
• a toroidal secondary winding disposed in inductive relationship around said magnetic core;
• a terminal board having substantially flat top and bottom surfaces;
• first, second and third terminals each including an upstanding body having sides extending between a top surface thereof and a lower shoulder portion having top, side and bottom surfaces extending radially outward at the bottom of said body, said body having an opening extending through the sides thereof and an internally threaded hole extending from the body top surface to said opening for threadably receiving a screw member for clamping an external lead conductor either to said top surface or within said opening, and said bottom surface of said shoulder portion carrying integral rivet means clamping said shoulder portion to said terminal board and further carrying integral wire connection means connected to said secondary winding below said terminal board;
• said third terminal including said lower shoulder portion having said top, side and bottom surfaces with said bottom surface mounted on said terminal board between said first and second terminals, and said body of said third terminal including an upper externally threaded portion for threadably receiving a nut member;
• an inverted U-shaped shorting bar having a center portion rotatably mounted on the upper portion of said body of said third terminal with the downwardly extending ends thereof being acruately movable about said last named body between a first position having said ends clamped by said nut member to said top surfaces of said shoulder portions of said first and second terminals and a second position having the bar ends disengaged from both of the shoulder top surfaces;
• a casing formed of a molded thermoplastic electrical insulating material surrounding said magnetic core, said secondary winding and said terminal board, and being disposed in fluid sealing relation therewith and with the side surfaces of each of the aforenamed shoulder portions so that said top surfaces of the shoulder portions remain exposed;
• and
• a terminal cover having a box configuration with a closed top and opposite ends and opposite sides terminating at an open bottom for mounting in first and second positions displaced one hundred and eighty degrees over said first, second and third terminals, one of said sides having lead conductor openings aligned with said first, second and third terminals when said cover is in the second mounted position for receiving external lead conductors connected to said first, second and third terminals, said top and the other of the cover sides including shorting bar interlock means formed by an indentation extending from a middle portion of the other cover side and a finger depending from the cover top at a predetermined location so that when said cover is in the first mounted position and said first, second and third terminals are to have a mutually shorted condition, said finger is positioned so as to be aligned with the space between said first terminal and said third terminal and offset therefrom so that both said finger and said indentation are clear of said first shorting bar position, and concurrently so that both are in interferring relationship with said second shorting bar position, and when said terminal cover is in the second mounted position said finger is positioned so as to be within the space between said second terminal and said third terminal so that said finger is clear of said second shorting bar position and concurrently so that said finger is in interferring relationship with said first shorting bar position.