What specifications should be used for fixing screws of internal components in African lighting electrical ready boards?
Material: Stainless steel (such as 304) or hot-dip galvanized screws must be selected. In rural areas of Africa, due to humidity and large temperature differences between day and night, ordinary screws are prone to rust, making them difficult to disassemble for future maintenance.
Size: Conventional components (such as small circuit breakers, rails): M4 or M5 screws (diameter 4mm or 5mm) are usually used. If it is directly fixed on the bottom plate of the electrical ready board, the length is generally selected as 10mm-12mm to ensure sufficient bite depth after screwing into the bottom plate.
High current components (such as isolating switches, surge protectors): or fixed to the base of the electrical Ready Board Box casing, M6 or M8 screws should be used to provide sufficient mechanical strength.
Do you need to equip with anti loosening washers? Why?
Must be equipped. And it is recommended to use the configuration of "one spring and two flat" for installation combination.
Specific configuration: On the bolt head side, place a large flat washer. Function: Increase the contact area to prevent damage to the plastic casing or paint surface of the components during tightening.
Nut side: First place a flat washer, then place a spring washer (must be tightly attached to the nut).
Necessity analysis (for African environment):
Anti vibration: In some parts of Africa, the road infrastructure is poor, and severe bumps during transportation can cause huge impacts on the internal connections of the electrical ready board. Spring washers have elasticity and can maintain pre tightening force during vibration, preventing screws from loosening due to vibration.
Coping with temperature difference: In rural areas, there is a large temperature difference between day and night, which can lead to thermal expansion and contraction of materials. Anti loosening washers can compensate for these small size changes and maintain the tightness of the connection.
Ensure electrical safety: If the fixing screws are loose, it may cause the wire connection points to heat up (due to increased contact resistance), and even trigger a fire. Anti loosening measures are a basic requirement for ensuring the long-term safe operation of electrical circuits