AC arc flash

The arc gives off intense heat, sound and pressure waves. It can set clothing on fire and cause severe or fatal burns. The risk comes up when work is done on exposed live parts, for example in panel boards and in the AC bus bar area of battery storage enclosures. AC arc flash is better understood than DC arc flash, and its industry calculation methods are backed by many equipment tests. Before work, check the arc flash label for the expected incident energy and the recommended PPE. On Megapack units, isolate them from upstream AC sources when working in the AC bus bar area or when the incident energy is above the allowed maximum. Never unplug connectors under load. Open the breakers and make the equipment inoperable before servicing. Lower the risk by following procedures, using the right tools, keeping up preventive maintenance and planning the work. Wear arc-rated clothing in case an arc still happens.

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• sentence 2: support check: partial - Exposed live parts work and the AC bus bar area isolation requirement are stated, but panel boards are only shown in a figure caption and 'battery storage enclosures' is not stated as such.
• sentence 6: support check: partial - Risk reduction measures are stated, and arc-rated clothing is the common PPE, but the passages do not explicitly say to wear arc-rated clothing in case an arc still occurs. -->