The inspection points for dust explosion-proof lighting distribution boxes include sealing, protection level, electrical connection, installation environment, identification and operation, intelligent function, and shell integrity. The following are specific instructions:
Sealing of inlet and outlet: Check if all inlet and outlet ports are tightly sealed with fireproof adhesive or fire-resistant partitions to prevent external dust from entering. According to the requirements of the "Code for Construction and Acceptance of Electrical Equipment in Explosive and Fire Hazardous Environments of Electrical Equipment Installation Engineering" (GB50257-2014), after the inlet is connected to the cable and wire introduction, the integrity of the cable introduction device and the sealing of the elastic sealing ring should be maintained. The clamping components need to be tightened with tools, and the inlet should be kept sealed.
Protection level verification: Confirm whether the protection level of the distribution box reaches IP66 or higher, ensuring that it can effectively prevent dust from entering the interior of the box and avoid fire and explosion accidents caused by electrical sparks or high temperatures.
Electrical connection inspection: Check whether the switches in the distribution box are intact and reliable, whether the wires are damaged, and whether the wiring specifications are loose or overheated; Whether the screws on the box terminals are tightened, free of oxidation, and whether the connecting wires are aged. Ensure that the metal box door and metal box body are effectively grounded through braided soft copper wire, and are connected by welding, crimping, or bolts. It is strictly prohibited to wrap or hook the connection.
Installation environment and space: Ensure that the distribution box is installed in a dry and well ventilated environment, with sufficient safety passages and operating space reserved around it, and that there are no flammable, explosive, or corrosive materials piled up in the area.
Identification and operation inspection: Confirm that safety warning signs related to electric shock prevention are prominently and easily recognizable on the door of the distribution box; Check whether the identification of each control circuit in the distribution box is clear and complete, for easy operation and maintenance.
Intelligent function inspection: For dust explosion-proof lighting distribution boxes equipped with intelligent functions, it is necessary to check whether their temperature monitoring, fault diagnosis, remote control and other functions are working properly. For example, the built-in temperature sensor should be able to monitor the temperature inside the box in real time and automatically sound an alarm when it exceeds the set value.
Shell and coating inspection: Check whether the shell of the distribution box is intact, without pits or scratches; Whether the coating is firm and uniform, without wrinkles, peeling, spots, missed spraying and other adverse phenomena. For the distribution box with aluminum alloy or stainless steel shell, its corrosion resistance and aging resistance shall also be checked.