Hardware
Do I need AFDD / arc-fault detection with home solar in South Africa?
AFDDs (arc-fault detection devices) are increasingly discussed for final circuits where series arcs start fires — solar does not remove that conversation, and DC arcs on the roof still need correct isolation, connectors and workmanship first. Follow the registered person’s design and the wiring rules applicable to your install; do not treat an AFDD as a substitute for bad MC4 joints.
Updated 27 October 2026 · Illustrative ranges — not a formal quote, credit decision or legal advice.
Answer first: Ask the electrician whether AFDDs are specified on any AC final circuits in your renovation or new DB, and separately confirm DC isolation, SPD and connector quality on the PV side. They solve different problems — DC isolation · MC4 faults · SPDs · earthing · CoC.
AC arcs vs DC arcs
| Domain | Primary controls |
|---|---|
| AC final circuits | Correct breakers, RCDs/AFDDs where specified, torque on terminals |
| PV DC | Matched connectors, isolators, string design, no live DIY |
| Hybrid AC out | OEM-compliant backup board, dual-supply labels — dual-supply labels |
When partners mention AFDD
- New DBs or major rewires in homes with higher fire-risk profiles.
- Circuits feeding complex loads after renovations.
- Insurance questionnaires that ask about arc protection — answer honestly — insurance.
What AFDD will not fix
Crushed DC tails under bird mesh, mixed MC4 brands, or missing DC isolators. Fix workmanship first — bird proofing · DIY risks · red flags.
Quote / CoC questions
- Are AFDDs included, optional, or not applicable on this design?
- Which circuits carry them?
- How are they coordinated with Type A/B RCDs on EV circuits? — RCD Type B
Related: DB upgrades · inspector tips · read a quote.
How to talk about AFDD without cargo-cult shopping
AFDDs detect certain arc signatures on AC final circuits. They are not a badge you bolt onto a hybrid to “make solar safer.” Start from the electrician’s circuit schedule and the applicable wiring rules for your project type — DB upgrades · CoC · inspector tips.
Coordination with EV and RCD devices
EV circuits already demand careful RCD selection (Type B or OEM-integral DC detection). Adding AFDD without a coordination plan creates nuisance trips or gaps — RCD Type B · EV wiring · wallbox vs portable.
DC-side fire prevention remains workmanship
- Matched MC4 (or listed) connectors fully mated.
- Correct DC isolators and labels.
- No live DIY under daylight strings.
- Bird-proofing that does not abrade insulation — MC4 · DC isolation · bird proofing.
Insurance questionnaires
If a form asks about arc-fault devices, answer from the CoC schedule. Guessing “yes” after a claim helps nobody — insurance · claims · battery fire myths.
Quote clarity
- AFDD included / optional / not applicable — stated explicitly.
- Circuits listed.
- Price Incl. VAT if optional.
- No claim that AFDD replaces DC isolators.
Related: read a quote · SPDs · earthing · red flags.
Series vs parallel arcs in plain language
Series arcs often hide in damaged conductors or loose terminals under load. Parallel arcs involve different potentials and can escalate faster. AFDDs target signatures on AC final circuits; PV DC arcs need isolation gear and intact connectors instead — MC4 · DC isolation · earthing.
Where SA homeowners meet the topic
- New builds or major DB upgrades where the designer specifies AFDD on selected circuits.
- Insurance or estate questionnaires after a neighbour’s electrical fire.
- EV + solar renovations that reopen the DB — DB upgrades · do I need a DB upgrade · RCD Type B.
Nuisance trip management
Like RCDs, AFDDs can nuisance-trip on some loads if selectivity is poor. That is a design issue for the registered person, not a reason to bridge out protective devices — inverter nuisance trips (different domain) · inspector tips · CoC.
Documentation that belongs in the folder
- DB schedule showing AFDD circuit IDs.
- OEM datasheets for the devices fitted.
- Coordination note with RCD types on EV circuits.
- Explicit statement that PV DC protection is separate.
Related: read a quote · SPDs · lightning · battery fire myths · red flags.
Bottom line for quote season
Pay for competent AC design and competent DC workmanship. An AFDD line item without connector discipline or isolators is theatre; isolators without any thought to AC final circuits on a full rewire may also be incomplete. Ask clear questions once, get them in writing, then compare partners on the same brief — choose installer · check a quote · NRS list.
Conversation starters for the registered person
- “Which final circuits, if any, carry AFDD on this design?”
- “How do they coordinate with the EV RCD topology?”
- “What nuisance-trip loads should we expect?”
- “Confirm PV DC isolators and connector standards remain as specified — AFDD is not a substitute.”
Write the answers into the quote pack. Related: RCD Type B · EV wiring · MC4 · DC isolation · DB upgrades.
After an AFDD trip
- Note which circuit ID dropped.
- Unplug or isolate suspect loads on that circuit.
- Call the electrician — do not bridge the device.
- If trips coincide with hybrid events, bring both diaries — inverter trips · fault codes.
Related: CoC · insurance · red flags · choose installer.
Training the household without fear-mongering
Tell family members which breaker is which and that protective devices are not to be permanently bridged. A tripped AFDD is information; a coin in the fuse holder is how fires restart — DIY risks · fire myths · DC isolation.
Practice one daylight shutdown drill yearly so Stage chaos is not the first time anyone looks for isolators — dual-supply labels · islanding · solar during shedding.
Related reading before you spend: read a quote · DB upgrades · RCD Type B · MC4 · SPDs.
Keep DC and AC stories in separate folders
One folder for PV DC photos (isolators, MC4s, string maps) and one for AC DB schedules (RCD/AFDD IDs) prevents mixed advice from well-meaning neighbours. When you phone for help, say which folder the symptom lives in — MC4 · DC isolation · DB upgrades · RCD Type B · CoC.
Quote annexure one-pager
Ask every partner for a one-page protection summary: RCD types by circuit, AFDD yes/no by circuit, DC isolator locations, SPD locations, and EV protection topology. Compare those one-pagers side by side instead of marketing brochures — read a quote · check a quote · red flags.
If a partner cannot produce that page, they are not ready for a complex DB + solar + EV job — choose installer · EV wiring · home charger cost · DB upgrade need.
Homeowner folder to keep with the CoC
Store the quote annexures, OEM manuals, serial photos, export-limit screenshots and metro reference letters together. When a future technician or buyer inherits the plant, that folder beats scattered WhatsApps — choose installer · selling with solar · warranty transfer.
Re-check fixed charges and tariff codes after any meter change so savings models stay honest — fixed charges · 2026/27 tariffs · metro tariffs hub · bill still high.
Field notes from SA handovers
At commissioning, ask the partner to demonstrate the behaviour described on this page, photograph settings, and confirm NRS-listed SKUs match the invoice. Refuse non-listed gear and export promises that ignore your metro’s live PDF — red flags · NRS list · SSEG · read a quote.
Coordination with EV RCDs
Where a Type B (or OEM-required) RCD protects an EV circuit, ask how any AFDD on nearby finals is coordinated so nuisance trips do not strand the wallbox — RCD Type B · EV CoC wiring · DB upgrades.
Insurance questionnaire honesty
If the form asks about arc-fault devices, answer from the CoC design — not from a brochure. Guessing "yes" to every safety acronym can backfire at claim time — insurance · CoC.
Quick questions
Does solar legally require AFDD everywhere?
Requirements depend on the wiring rules and the circuit design — ask the registered person; do not assume a social-media rule.
Will AFDD stop roof DC arcs?
No — DC arc risk is managed with isolation, connectors and workmanship on the PV side.
Should I add AFDD myself?
No — final-circuit protection belongs in a CoC design.