Abstract: A multipurpose wire connection device includes a base plate, a conductive plate, a wire fixation screw, a fireproof box, a support, and a dustpan-shaped housing. The support is disposed on the base plate. The fireproof box includes a rear panel, a bottom panel, two side panels, and an inserted plate. The wire fixation screw is mounted on the conductive plate. The housing is fixed on the bottom plate by a housing fixing screw. The multipurpose wire connection device prevents sparking and red burning of a ground screw when lightning current passes therein, due to corroded contact in long-term exposure to wind and rain. It avoids fire and explosion accidents. It avoids screw corrosion and facilitates ground resistance measurement. The multipurpose wire connection device can also be used for electrical relay, division, and branching. It prevents fire, explosion, rain intrusion, and rust development. It is easy to disassemble.

Abstract: A mechanical fault indicator of the automatic reset includes the core, the dial, the lock, the indicating rods, and the shell. The core includes the clip-on core, fixed core, connecting core and movable iron core. The pointer includes the indicating axis of rotation, the pointer connection and the indicating rod. The lock includes the lock axis of rotation, the lock hook and balancing weight. When using the indicator, clip the wire of the transmission line into the two-part clip-on core. When a short circuit fault happens, the indicating rod falls out of the housing, of which the action indicates failure. When the circuit is back to normal, the indicating rod resets automatically. The indicator has the advantages of: low cost, long service life, purely mechanical, no circuit and battery, and the installation is simple and convenient.

Abstract: A mechanical fault indicator of the automatic reset includes the core, the dial, the lock, the indicating rods, and the shell. The core includes the clip-on core, fixed core, connecting core and movable iron core. The pointer includes the indicating axis of rotation, the pointer connection and the indicating rod. The lock includes the lock axis of rotation, the lock hook and balancing weight. When using the indicator, clip the wire of the transmission line into the two-part clip-on core. When a short circuit fault happens, the indicating rod falls out of the housing, of which the action indicates failure. When the circuit is back to normal, the indicating rod resets automatically. The indicator has the advantages of: low cost, long service life, purely mechanical, no circuit and battery, and the installation is simple and convenient.

Abstract: A device and a method are described for online monitoring the lifespan of switch contacts of a transformer on load tap changer (OLTC). The method includes connecting a current signal sensor of a voltage adjustment winding of the power transformer with a current signal processing circuit thereof; connecting the current signal sensor with an analog-digital converter of an industry control computer (IPC). When a switch signal is received, the switch current value and the number of switching operation of the OLTC are used for comparison with a lifespan relationship as a function of number of switch operations of a switch contact having similar specifications, wherein the relationship indicates a critical current value indicating the need for replacement. The device includes the IPC, the signal processing circuit, a monitor, and a keyboard.