Box core module, plug module, and surge protective device (SPD)

A plug module, comprising a housing, a bottom plate, a plurality of box core modules with an independent tripping mechanism, a first pin electrode, and a second pin electrode, wherein each of the plurality of box core modules comprises a box core frame, a voltage-limiting element, a spring electrode, and a tripping mechanism, wherein

• the voltage-limiting element and the spring electrode are respectively arranged on front and back sides of the box core frame,
• the voltage-limiting element comprises a pin electrode and a tripping electrode, wherein the tripping electrode of the voltage-limiting element and one end of the spring electrode are welded using a fusible alloy,
• the tripping mechanism acts on the spring electrode,
• the tripping mechanism always separates the tripping electrode from the spring electrode when the fusible alloy is melted,
• the pin electrode of the voltage-limiting element is led out from a side surface of the box core frame to form a first module electrode of the box core module,
• an electrode of the tripping mechanism is led out from a bottom surface of the box core frame to form a second module electrode of the box core module;
• the plurality of box core modules are vertically arranged on the bottom plate in a same direction and side-by-side manner, and the plurality of box core modules are connected by a first internal connection electrode to form a parallel combined line;
• or
• the plurality of box core modules are vertically arranged on the bottom plate in an opposite direction and side-by-side manner, and every two adjacent box core modules are connected by a second internal connection electrode to form a series combined line;
• wherein the parallel combined line or the series combined line is led out through the first pin electrode and the second pin electrode.