The small power distribution box we usually use is to assemble the switchgear, measuring instruments, protective electrical and some auxiliary equipment in a closed or semi closed metal cabinet (which can also be installed on the screen) according to the electrical wiring requirements to form our common low-voltage distribution device. During normal operation, the circuit can be switched on or off with the help of manual or automatic switches. In case of failure or abnormal operation, the circuit will be cut off or alarm will be given with the help of protective appliances. According to the measuring instrument, various parameters in operation can be displayed, and some electrical parameters can be adjusted to prompt or signal deviation from the normal working state. It is often used in rural families. Now let's understand it a little bit. If there is a junction box, the sundries in the box shall be removed first, then the wires shall be straightened out, the branch and phase sequence shall be distinguished, and the bundle shall be bound according to the branch. After the box (panel) is located correctly, lead the end of the conductor to the box or panel, one by one exploit the end of the conductor, and then crimp it to the appliance. At the same time, press the PE protective ground wire to the obvious place, and fix the box (panel) after it is adjusted and straightened. After the installation of panels with many electrical appliances and instruments, the instrument should be used to check whether there is any error. After the adjustment is correct, try to power on the cards, and fill in the position and number the cards in the card box. When piping is laid in a concealed manner in the fender wall and there is a concealed junction box, the opening of the box shall be flush with the wall, and fire protection facilities shall be provided at the wooden fender wall.