A vacuum contact enclosure has end contact assemblies within contact enclosures specially formed to distribute the high voltage field and eliminate high stress in an encapsulating solid insulation. A non-tracking guide tube extends concentrically of a movable contact rod. A solid, dry, high voltage insulation wall intimately attaches to the vacuum and contact enclosures. The wall has an opening through which the contact rod extends with a planar end wall surface abutting a submersible operating housing. A clamp engages the wall and housing and draws the wall surface into sealing engagement with the housing. The operating mechanism includes a pivoted lever assembly connected to a spring-loaded linkage member secured to the contact operating member and a spaced drive lever and pin assembly. A toggle assembly is pinned between the assemblies and includes a releasable latch member. An extension spring is connected at opposite ends to the lever assemblies to rapidly open the contacts upon release of the latch member. A separate closing spring is connected to the lever and pin assembly. A trip-free operating handle has a reset arm engaging a pivoted arm for pivoting the lever and pin assembly to reestablish the toggle latch and simultaneously stress the both extension springs. The reset arm disengages and releases the mechanism and the closing spring pivots the reset toggle mechanism to close the contacts.