Safety isolation

Safety isolation means fully separating the affected part of the installation from every possible source of electrical power before anyone works on it. For junction box failures, isolation should be the first priority whenever there is evidence of arcing or burning. Repair, such as replacing the module or junction box assembly or fixing wiring and sealing defects, comes after that. Junction box failures can cause internal arcing, insulation faults and even fires, which is why they are a serious hazard to anyone near the module. An insulation fault in cables or connectors can leave conducting parts at potentially fatal voltages. Damaged cables or connectors can also cause arcs and start a fire. Touching uninsulated parts can cause severe injury unless safety gear and safe measuring instruments are used. PV array circuits stay live in daylight and cannot always be isolated before testing. In that case, restrict access to the work area, keep people away from metal surfaces and module terminals, and wear suitable protective equipment. When an inverter arc-fault circuit interrupter detects an arc and blocks operation, the block must be reset manually.

<!-- review notes

• sentence 2: support check: partial - The passages say to prioritize safety isolation for arcing or burn evidence and list repair actions, but do not state that repair comes after isolation as an explicit sequence.
• sentence 6: support check: partial - The passage gives these measures, but it says the circuits are live during the day and cannot be isolated before this test (the insulation test), not that they cannot always be isolated before testing in general. It also calls them 'courant alternatif' circuits. -->