Solis ARC-FAULT: DC Arc Detected
This is a fire-risk safety code.
ARC-FAULT means the Solis arc-fault detector (AFCI) sensed an electrical arc in the DC (solar panel) wiring. An arc is a genuine fire hazard. Do not simply clear it and walk away, and do not keep resetting it.
ARC-FAULT (code 1041) is an arc-fault alarm. The inverter listens to the DC side for the electrical signature of an arc, which usually comes from a loose, corroded or damaged connection in the panel wiring, most often an MC4 connector. Because arcs can start fires, the Solis shuts down and raises ARC-FAULT deliberately.
What causes an arc fault
- A loose or poorly crimped DC connector (MC4), the most common cause.
- Corrosion or water ingress in a connector or junction box.
- Chafed or damaged DC cable insulation.
- A burnt or melted connector from an earlier hot joint.
What to do, safely
Important Inspecting and repairing DC panel wiring is a qualified-installer job. PV strings are live whenever there is daylight and cannot be switched off at the panel. The steps below are about doing the safe thing, not about you opening connections.
- Look for danger signs. If you can safely see the inverter and DC cabling, check for smoke, a burning smell, or scorch and melt marks. If you find any, shut the system down at the isolators if it is safe to do so and treat it as an emergency.
- Do not keep clearing the alarm. Resetting it without finding the arc simply re-energises a possible fire hazard.
- Shut down per your procedure. Turn off the AC breaker and the DC isolator following your installer's shutdown sequence.
- Call your installer or a licensed solar electrician. They inspect every DC connector and cable, find and fix the arcing joint, and only then clear the fault. (They may also review the AFCI sensitivity and firmware.)
Why we don't give a DIY fix here
Unlike a load or cooling code, an arc fault is a fire-safety issue in live DC wiring. The responsible advice is to shut down and get a qualified person to inspect and repair the connections. We won't tell you to open DC connectors yourself.
Related Solis codes
FAQ
ARC-FAULT cleared by itself. Am I fine?
Not necessarily. An intermittent arc can come and go with temperature, load and movement. If it has shown even once, have the DC connections inspected. An arc that "went away" can return worse.
Could it be a false alarm?
AFCI can occasionally nuisance-trip, and Solis lets installers review the sensitivity and firmware, but never assume that. Treat every ARC-FAULT as a real arc until a qualified inspection proves the wiring is sound.
Sources
- Solis inverter alarm-code list (ARC-FAULT = detected DC arc; inspect MC4 connections, check panels, review firmware/sensitivity).
- General PV arc-fault (AFCI) safety guidance for DC string wiring.
⚠️ Safety disclaimer. An arc fault is a fire hazard. Solar DC wiring is live in daylight and cannot be switched off at the panels. This guide is educational only and deliberately does not instruct you to open or repair DC connections. Shut the system down per your installer's procedure and call a licensed solar electrician.