Arc-fault protection on a photovoltaic array is there to notice an arc on the DC conductors and to stop it. An arc is current jumping a gap or tracking across damaged insulation, and it makes heat. The function is supposed to shut the inverter down, or otherwise interrupt that circuit, when it decides an arc is present. If the screen says the function tripped, treat the array as needing a qualified person. A trip you would like to call a nuisance is still a trip.
The conductors it is watching
The watch is on the DC side: module leads, connectors, wiring from the array to the inverter. A series arc is along a conductor that has opened, loosened, or corroded, so the current the string is already carrying has to jump. A parallel arc is between conductors, or from a conductor toward ground. You do not need the subtype to make the decision. You need the code on the screen and a person who is allowed to inspect those conductors. This page will not describe how to produce an arc, and it will not list a connector-by-connector procedure.
Loose or heat-damaged connectors are a common place technicians look, because a connector is a joint in the DC path. Looking is their work, with the array made safe by the method their training and the equipment listing require. An owner pulling connectors apart on a sunny roof is not that inspection. Daylight keeps the modules able to produce voltage.
A trip that seems to clear itself
An arc can start, quench, and start again as a joint heats and cools or as the wind moves a lead. The inverter may run for an hour after a reset and then stop. That pattern is a reason to quit resetting, not a reason to decide the detector is fussy. A reset clears a latch. It does not remake a damaged joint. If the code returns, stop and hand over the times and the photos.
A ground-fault alarm is a different claim: current has a path to ground the design did not want. An arc along a broken series joint may never be that path. Both alarms can take production offline. What a PV ground fault means is the page for the ground-fault light. Do not clear one by treating it as the other.
A different job from anti-islanding
Anti-islanding watches the utility connection. Its job is to stop the inverter energizing a line the utility has left, so a worker or a neighbor is not fed by your array. Arc-fault protection watches the DC wiring on your side of the inverter. Both can shut the system down. They answer different hazards, and defeating either one to "get the kilowatt-hours back" removes a function the listing put there. The long account of anti-islanding stays in what anti-islanding is. The wider set of inverter protections, including how they differ, is in protection functions of a solar inverter.
Write the code, the time, and whether anything on the roof was worked on recently. Give that note to the person who will inspect. A detector that trips every bright noon, and only then, is still their problem to explain. Sun makes current. Current is what an arc needs. The correlation does not make the trip imaginary.
After the inspection, ask what was found and keep that note with the commissioning folder. A connector that was reseated, a lead that was rubbed through on a rail, or a detector the technician condemns are different endings, and only the note tells them apart a year later. Production returning the same afternoon is not, by itself, the ending. The path that arced can cool and wait.
