As the core node of the electrical system, the safety performance testing of the lighting electrical ready board after maintenance is the last line of defense to ensure electrical safety. Through a systematic detection process, potential hazards can be identified in a timely manner, and risks can be nip in the bud.

Insulation resistance testing is the primary step. Use a megohmmeter to test the insulation performance between the main circuit, control circuit, and enclosure, and the resistance value should not be less than 0.5M Ω. Before testing, it is necessary to disconnect all levels of circuit breakers to ensure that the capacitors are fully discharged and to avoid misjudgment caused by residual current. Focus on detecting phase to ground, neutral to ground, and phase to phase insulation, especially for old lines that require layered shake testing to accurately locate weak insulation points.

Grounding system testing follows closely behind. Measure the power frequency grounding resistance of the grounding device using a grounding resistance tester to ensure that it is not greater than 4 Ω. It is necessary to check whether the grounding main line and the box are connected by double bolt crimping. If the corrosion area of the grounding flat iron exceeds 1/3, it should be replaced immediately. The TN-S system needs to verify that the PE line is fully connected throughout the entire process, and it is strictly prohibited to have disconnected or mixed neutral lines.

The verification of the leakage protection function adopts the simulated leakage method, injecting the rated residual current value into the circuit through a dedicated tester to verify whether the circuit breaker can reliably operate within 30mA. During testing, the protection level coordination between the main box and branch boxes should be verified step by step to prevent overstepping tripping and expanding the power outage range. For special places such as operating rooms and swimming pools, it is necessary to adjust the movement parameters according to regulations and affix warning signs.

The loaded operation test will be conducted at the end of the test. After closing, use an infrared thermometer to scan the surface of the box. Areas with a temperature rise exceeding 30 ℃ need to be checked for poor contact. Monitor the balance of three-phase current through intelligent sensors, and check the load distribution when the deviation exceeds 15%. During night patrols, special attention should be paid to whether there are any abnormal discharge sparks in the electrical ready board to ensure that the maintenance quality can withstand practical testing.

The testing process needs to be fully recorded and archived, with key parameters recorded in an electronic ledger. This' physical examination style 'testing is not only the ultimate inspection of maintenance quality, but also an important link in building an electrical safety closed-loop management, laying a solid last line of defense for the stable operation of the lighting system.