What is the proper method for inspecting a GPU cable for damage before connecting it to an aircraft?

The proper method for inspecting a Ground Power Unit (GPU) cable before connecting it to an aircraft involves a systematic visual and physical examination to ensure its integrity and prevent electrical hazards. Begin by visually inspecting the entire length of the cable for any signs of external damage, such as cuts, abrasions, cracks, or exposed wires. Pay close attention to areas where the cable may have been subjected to stress or wear, such as near connectors or where the cable has been bent or coiled. Check the cable's insulation for any signs of discoloration or swelling, which may indicate internal damage or degradation. Examine the connectors at both ends of the cable for damage, such as bent or broken pins, loose connections, or corrosion. The connectors should be clean and free of debris. Gently flex the cable along its length to check for internal breaks or shorts. If you feel any unusual stiffness or resistance, this could indicate a problem with the internal wiring. Use a multimeter to test the continuity of each conductor in the cable. This test ensures that there are no breaks in the wires and that each conductor is properly connected to its corresponding pin in the connector. Also, use the multimeter to test for shorts between the conductors and the cable's outer shield. There should be no continuity between the conductors and the shield. Inspect the cable's grounding wire and ensure it is securely connected at both ends. The grounding wire is essential for preventing electrical shock. Check the cable's strain relief devices, which are designed to protect the cable from being pulled or stressed at the connectors. Ensure that these devices are properly attached and functioning correctly. If any damage or defects are found during the inspection, the cable should be immediately taken out of service and tagged for repair or replacement. Never attempt to repair a damaged GPU cable yourself unless you are a qualified electrician. Using a damaged GPU cable can result in electrical shock, damage to the aircraft's electrical system, or even a fire.