Material selection of arc extinguishing chamber for circuit breakers in rural lighting Ready Board Box in Africa

Adapting to the high temperature, strong ultraviolet radiation, frequent sandstorms, and high humidity condensation environment in rural Africa, the circuit breaker arc extinguishing chamber of the lighting ready board in rural Africa needs to be layered with arc resistant gas producing insulation shell and magnetic arc extinguishing grid, taking into account efficient arc extinguishing, arc short circuit resistance, and durability in harsh weather conditions.

The main body of the arc extinguishing chamber shell is made of fiberglass reinforced DMC unsaturated polyester molding material, combined with modified arc resistant PA66 gas producing lining. Under the high temperature of the arc, the material decomposes to produce cooling gases such as CO ₂ and H ₂, forming an internal gas blowing to elongate the cooling arc and rapidly reduce the arc temperature; The material has a UL94 V-0 flame retardant rating and is resistant to arc burning, making it difficult to carbonize and form conductive channels, preventing arc creeping short circuits along the wall. It is also resistant to ultraviolet radiation and has low water absorption, making it suitable for working conditions in Africa with large temperature differences between day and night and frequent condensation.

The internal arc extinguishing grid is made of nickel plated low-carbon steel, which relies on a magnetic field to cut the long arc into multiple short arcs and quickly extinguish the arc using the near cathode effect; The nickel plating layer resists the corrosion of sand, dust, and water vapor, avoiding the failure of the grid due to rusting and breakage. The arc starter is made of copper tungsten alloy, which has a high melting point and is resistant to arc erosion. It guides the arc to quickly enter the grid and protects the main contact from being welded and adhered.

The partition auxiliary material is matched with GPO-3 arc resistant insulation board, which has a high resistance to leakage and trace index. Even after sand and dust accumulation, the insulation strength is maintained to prevent phase arc short circuit. The entire material combination can stably break short-circuit current at high temperatures above 45 ℃, extinguish arcs in milliseconds, and is suitable for rural lighting ready boards in Africa. It eliminates the hidden dangers of phase to ground short circuits caused by arc leakage and continuous arc burning from the material level.