Research on thermal decomposition and combustion characteristics of distribution lines and components in residential community

• A combined TG-FTIR and cone calorimeter system was established to compare three typical distribution materials. • The study revealed differences in decomposition temperature ranges and gas products, clarifying the pyrolysis mechanism. • Fire hazards were evaluated using multiple indices, showing the smart meter material posed the highest risk. • The results support fire-safe material selection and fire origin analysis in residential power systems. In recent years, electrical fires have occurred frequently in residential areas, causing serious casualties and property damage. In order to provide fire protection parameters, this study investigated the thermal decomposition and combustion characteristics of key distribution line components, including conductor insulation layers, air circuit breakers, and smart meter housing materials (PVC, PA, and PC). The results of the thermogravimetric infrared experiment showed that PVC had the lowest decomposition temperature (200℃), PC had the highest decomposition temperature (332℃), and PA had a decomposition temperature between the two (285℃). The order of quality loss is: PC (96.61%) > PVC (85.74%) > PA (71.61%). The pyrolysis process of the three materials is divided into two stages, and the main gases released include H 2 O, CO, CO 2 , HCl, and aromatic and aliphatic compounds. The cone calorimeter test showed that the heat release rate, smoke production rate, O 2 consumption, and CO/CO 2 production rapidly reached their peak and then gradually decreased, and there was a significant correlation between smoke production rate, O 2 consumption, and CO/CO 2 production and heat release rate. Based on these parameters and FPI/FGI index, the fire hazard ranking is PC > PVC > PA.