The ANSI Type A three insulator vertical break has been available to the electric power industry since the early 1920's. With one of the two hinge insulators rotating and controlling the opening and closing of the blade through various linkage designs, these switches became one of the preferred types for three pole gang operation from the ground level. As voltage, continuous current and short-circuit current ratings increased, further improvements in switch design evolved. In the mid 1960's, for example, a new and patented feature was incorporated in the basic angle pin design, and a locking feature was added to the jaw end of the closed switch blade. Finally, in the late 1960's the patented MK-40A (aluminum design), and MARK-40 (copper design) was introduced that incorporated the blade counter-balancing spring within a tubular housing which in turn conducted the current from the blade to the hinge terminal.

Since its beginning, Turner Electric has been known for the quality of its products. The addition of the DELTA-STAR product line has only added to the legend.

Vertical Break Switches
TMK40/40A
345 kV through 765 kV; 600, 1200 and 2000 available. 3000 and 4000 Ampere available on some ratings.

Distribution Switches
TB-2P
15 kV through 34 kV; 2000 Amperes standard

Motor Operators
SF100/SF200
48 VDC and 125 VDC; two-speed, high speed

Vacuum Interrupters
TJV-1
Hook or load current interruption up to 169 kV possible