To prevent explosions or fires caused by the electrical equipments, every effort should be made. As aprerequisite. to minimize possible danger of explosion at a location where they are to be installed.

The electrical equipments should be installed at a location with a minimum posibility of explosion. In case, however. they are unavoidably installed at a hazardous location where explosion is expected, It should be limited to a minimum extent.

The explosion-proof electrical equipments to be installed should be the products that have been proved to fully meet the requirements.