Recharging fuses PN-2

Fuses with replaceable fuses are used in electrical installations. In water distribution devices, entire transformer substations, in measuring and distribution boards and cabinets, PN-2 fuses are most often used.

PN-2 fuses consist of a shell filled with quartz sand, a fusible link, contact bases and an insulating base.

Closed-cartridge, full-fill fuses allow multiple reloads after firing. When reloading, it is necessary to use replaceable calibrated fuses.

To fill or replace the filler, clean quartz sand without impurities (metal shavings, clay, etc.) is used.

The procedure for disassembling a PN-2 actuated fuse holder:

1. Unscrew the screws and remove the covers without damaging the asbestos seal and the porcelain pipe, and pour the sand.

2. Clean the inner cavity of the pipe, clean the file with a lump, the contact surface of the washer from the remnants of the fusible link.

Assembling the fuse PN-2 after reloading:

1.Weld or solder the fuse to one contact washer and then to the other. Irradiate the insert leads before soldering.

2. Place one cover with asbestos gasket on the contact assembly and fasten with screws.

3. Place the assembled assembly into the pipe and tightly screw the cap onto the pipe with the screws.

4. Turn the cassette 180 ° and cover it on top with dry quartz sand. Filling should be done in parts, periodically hitting the cartridge with a piece of wood to shake the sand until its level stops decreasing. Before reloading the cartridges, quartz sand must be dried at a temperature of 105-130 ° C.

5. Place the second cover with an asbestos gasket and screw it to the pipe.

When placing the covers, you need to monitor the tightness of their fit so that the sand does not spill.