Arc Fault Circuit Interrupter (AFCI)
A safety device that detects dangerous electrical arcs (sparks) in wiring and disconnects the circuit. Required by NEC in most living spaces and now in solar systems to prevent rooftop fires.
Why It Matters
Solar arc fault detection is a code requirement. Modern inverters include built-in AFCI protection, which is one reason to choose UL-listed equipment.
Related Terms
NEC (National Electrical Code)
The U.S. standard for electrical installation safety (NFPA 70). Article 690 specifically covers solar PV systems, including wiring, grounding, labeling, and rapid shutdown requirements.
Rapid Shutdown
An NEC (National Electrical Code) safety requirement that solar systems must be able to reduce rooftop DC voltage to safe levels within 30 seconds of initiating shutdown, protecting firefighters and first responders.