Packaged electrical transient surge protection

In apparatus preventing transient electrical surges in a circuit from an upstream power source from proceeding downstream, including voltage-limiting varistor means bypassing associated surge currents to ground, the improvement comprising

• in the circuit from the power source to the varistor means,
• current-limiting distributed resistance fuse link means,
• and temperature-limiting fusible thermal cutoff means responsive to the temperature of the varistor means and adapted to open the circuit at a temperature below temperatures intolerable to the varistor means,
• wherein the varistor means includes a plurality of stacked varistors connected in parallel circuit by interleaving them with laminar connectors.

Packaged means to protect downstream electrical equipment from transient electrical surges from an external power source with a plurality of power lines, comprising a housing polygonal in plan, accommodating leads between its interior and the exterior at one end, and covered with a cap at the opposite end, containing therein

• a plurality of disklike varistors as over-voltage conductors,
• a plurality of terminal means along housing sidewalls flanked individually by a pair of sidewalls lacking such means,
• each such varistor having one of its faces in conductive contact with such sidewall terminal means and its opposite face in conductive contact with grounding means, and
• thermal cutoff means
• adjacent a sidewall other than a sidewall having a sidewall terminal means thereadjacent, and
• interconnected in circuit between such a power source and such sidewall terminal means.