Link disconnect box for an electrical distribution network protector

A method for field retrofitting of a network protector in a voltage distribution network, the method comprising:

• removing at least a secondary power line from an existing output terminal of the network protector;
• electrically and mechanically coupling a link disconnect box to the existing terminal of the network protector;
• and
• electrically and mechanically coupling the at least a secondary power line to the link disconnect box;
• wherein the link disconnect box comprises:
• an outer casing defining a cavity, a top bus bar opening, and a bottom bus bar opening;
• a top terminal disposed over the top bus bar opening, the top terminal configured to mechanically and electrically couple to the at least a secondary power line;
• a bottom terminal disposed over the bottom bus bar opening and configured to electrically and mechanically connect to the existing terminal of the network protector;
• a top bus bar electrically coupled to the top terminal and extending through the top bus bar opening;
• a bottom bus bar electrically coupled to the bottom terminal and extending through the bottom bus bar opening, wherein an air gap electrically isolates the top bus bar from the bottom bus bar within the cavity;
• and
• an electrical link configured to electrically connect and disconnect the top bus bar and the bottom bus bar by electrically bridging the air gap.

A link disconnect box for a voltage distribution network, the link disconnect box comprising:

• an outer casing defining a cavity, a top bus bar opening, and a bottom bus bar opening;
• a top terminal disposed over the top bus bar opening;
• a bottom terminal disposed over the bottom bus bar opening and configured to electrically and mechanically connect to an existing terminal of a network protector in the voltage distribution network;
• a top bus bar electrically coupled to the top terminal and extending through the top bus bar opening;
• a bottom bus bar electrically coupled to the bottom terminal and extending through the bottom bus bar opening, wherein an air gap electrically isolates the top bus bar from the bottom bus bar within the cavity;
• and
• an electrical link configured to electrically connect and disconnect the top bus bar and the bottom bus bar by electrically bridging the air gap;
• wherein the bottom terminal comprises a bottom terminal plate covering the bottom bus bar opening and connected to the bottom bus bar, and a terminal adapter plate removably connected to the bottom terminal plate, the terminal adapter plate comprising a first surface configured to mechanically and electrically engage with the bottom plate terminal, and a second surface configured to mechanically and electrically engage with the existing terminal of the network protector.

A link disconnect box for a voltage distribution network, the link disconnect box comprising:

• an outer casing defining a cavity, a top bus bar opening, and a bottom bus bar opening;
• a top terminal disposed over the top bus bar opening;
• a bottom terminal disposed over the bottom bus bar opening and configured to electrically and mechanically connect to an existing terminal of a network protector in the voltage distribution network;
• a top bus bar electrically coupled to the top terminal and extending through the top bus bar opening;
• a bottom bus bar electrically coupled to the bottom terminal and extending through the bottom bus bar opening, wherein an air gap electrically isolates the top bus bar from the bottom bus bar within the cavity;
• and
• an electrical link configured to electrically connect and disconnect the top bus bar and the bottom bus bar by electrically bridging the air gap, the electrical link configured to be mechanically secured in a closed position in which the air gap is bridged, and to fall under gravity into an open position in which the air gap is not bridged when not mechanically secured in the closed position;
• wherein the electrical link comprises a swing arm for bridging the air gap, the swing arm comprising at least an opening, and wherein the upper bus bar comprises at least a threaded hole corresponding to the at least an opening in the swing arm, and a bolt disposed through the opening in the swing arm engages with the threaded hole in the upper bus bar to mechanically secure the link in the closed position.