Compliance & hardware
Inverter fault codes in South Africa — when should I call the installer?
Capture the exact code, screenshot the app, check only the safe obvious items, and call if isolation, earth, battery thermal or repeating grid-code trips appear. Fault codes are not a licence to bypass protection.
Updated 27 October 2026 · Illustrative ranges — not a formal quote or legal advice.
Answer first: An inverter fault code is a symptom label, not a DIY repair manual. Note the exact code, screenshot the app, check the obvious safe items (AC breaker, PV isolator state, grid status, battery SOC), then call the installer or brand support if it repeats, involves isolation/earth, battery temperature, or grid-code trips. Do not bridge safety relays or “clear” isolation faults to keep the kettle on.
What to capture before you phone
- Exact code string and plain-language message (e.g. “Grid Overvoltage”, “ISO Fault”, “Batt Temp High”).
- Time stamp, weather, load-shedding stage, and whether the grid LED was on.
- App screenshot + serial / firmware version.
- What changed recently — new DB work, EV wallbox, panels cleaned, firmware update, storms.
- Whether the system is exporting, zero-export, or islanded on backup.
Families of faults (brand-agnostic)
| Family | Typical meaning | First safe check | Call sooner if… |
|---|---|---|---|
| Grid voltage / frequency | Utility outside inverter window | Confirm municipal outage / Stage; note neighbour reports | Repeats every evening peak on a healthy grid day |
| Isolation / insulation (ISO) | PV string leakage or moisture path | Do not touch array wiring in rain; isolate PV | Any damp-weather repeat — shock/fire pathway |
| Battery BMS / temp / comms | Pack protecting itself or lost CAN | Check SOC, ambient heat, cable seating only if trained | Swelling smell, thermal warnings, repeated BMS hard trips |
| Overload / short / inverter temp | AC load or thermal limit | Shed large loads (geyser, oven, wallbox); clear vents | Trips under modest load — possible wiring or unit fault |
| Relay / GFCI / RCD | Protection device opened | Do not hold-in breakers; call registered person | Any earth-leak pattern after EVSE install |
| No-grid / island | Backup mode or anti-islanding | Expected in load shedding if hybrid; check essential DB | Won’t reconnect when grid returns |
Brand manuals (Sunsynk/Deye, Victron, Growatt, Goodwe, Kodak-class, SolarEdge, etc.) list exact hex/numeric codes — use the OEM PDF for your firmware. This page intentionally does not invent code tables.
When it is urgent
- Burning smell, discoloured breakers, hot wall plates.
- Isolation / earth-fault codes that return after reset.
- Battery thermal or swelling warnings — see also Pylontech swelling questions.
- Faults that started the day an EV charger was added — possible shared-neutral or RCD type mismatch (EV wiring).
When a reboot is reasonable
One-off grid flicker during Stage transitions often self-clears. A single app reconnect after municipal restoration is normal. Three trips in a week with the same code is a service call, not a lifestyle. Keep a paper note of resets — technicians need frequency, not vibes.
Warranty and CoC angles
Unregistered firmware hacks, grey-import cables and bypassed earth monitors can void warranty and complicate insurance. PV GreenCard / registered-person paper trails help — GreenCard, CoC, NRS-approved inverters. If you are still inside workmanship warranty, the installer — not WhatsApp strangers — owns the first response.
Load shedding vs real faults
Hybrids should island cleanly on essential loads. If lights die every Stage 2, you may have oversized essentials, a failed ATS path, or a battery that is empty from overnight EV charging — solar in load shedding, ATS, essential loads.
Firmware and grey imports
Wrong firmware channels and grey-market Wi-Fi dongles create mysterious “faults” that are really cloud auth failures. Stick to OEM update paths your installer supports. If a Facebook group tells you to flash a file to unlock export beyond your metro permission, walk away — that is both a compliance and a warranty problem (max SSEG kW, DIY risks).
What a good technician visit looks like
They reproduce the code, check torque and glands, megger or isolation-test when relevant, read BMS logs, confirm NRS settings match the metro, and leave a written finding. They do not only power-cycle and invoice. Ask for the code history export from the logger. If the unit is swapped, keep the failed inverter’s serial for warranty.
After EVSE work, request an RCD/earth re-check on the shared DB. Many “random” hybrid trips start the week a 32 A wallbox lands on a marginal board.
Document for insurance and warranty
If a fault precedes a fire, surge or battery event, your notes and screenshots become claim evidence. Do not factory-reset logs before the assessor or OEM asks. Photograph the DB, SPD status and wallbox isolator state. That discipline also shortens installer diagnostic time — which shortens your downtime.
Keep OEM support ticket numbers with the installer WhatsApp thread. When a board-level component is replaced, confirm NRS 097 settings and export limits were restored to the permitted values — silent resets to factory defaults create export-compliance surprises later.
Educational only — not a substitute for OEM diagnostics or a registered person’s site visit.
Meter, export and “ghost” faults after SSEG go-live
Some codes appear only after the metro enables export or swaps the meter. The inverter may be fine; the AMI register, CT orientation or zero-export clamp may be wrong. Before you condemn the hybrid, ask whether the fault started the same week as SSEG activation, a prepaid-to-credit change, or a firmware push that reset NRS 097 windows. Capture export kW from the app at the moment of the trip — installers use that to separate grid-voltage nuisance from real isolation faults. See SSEG registration and net billing.
EVSE schedule vs inverter overload
A 7.4 kW wallbox that starts at 22:00 on a cold Highveld night, while the geyser element and a heat pump still finish their cycles, will look like an “inverter fault” on a 5 kW hybrid. It is often just overload protection doing its job. Stagger EVSE start, drop charge current one step, and move geyser windows to solar midday before you book a board-level repair. Log the amp setting that stops the trip — that becomes useful evidence on the service call. Pair with EV load management and essential loads.
If the unit reports battery-comms loss only when the wallbox is drawing, check shared earth/neutral paths and DC cable routing near the EVSE rather than swapping the pack first. Savings stay intact when you fix the schedule; they evaporate when you impulse-buy a bigger inverter for a timing problem.
Before you call — bill and settings sanity
Many “faults” are settings: grid-charge blocked on a prepaid meter, export limit tripped, Min SoC raised after a firmware push, or a CT reversed after a DB change. Screenshot the code, SoC, grid arrows and today’s kWh before rebooting. Note whether the bill’s tariff period just flipped — a sudden import spike can look like a failed battery when the hybrid simply followed a TOU schedule.
Call when you smell heat, hear relay chatter loops, see earth-leakage trips, or lose backup during a known Stage slot with SoC still high. Keep the CoC, NRS certificate and serials handy — CoC · NRS inverters.
Log before you panic
- Screenshot the app fault code, timestamp and AC/DC voltages.
- Note weather, Stage slot, and whether the grid was present.
- Check isolators, RCD trips and any dual-supply labels still intact.
- Call the installer with that pack — not a vague “it beeped.”
Repeated ground-fault or isolation alarms after rain can be wiring or moisture ingress; do not keep resetting without a CoC-holding electrician — CoC · earthing · surge / lightning.
Warranty clock
Unlogged DIY resets and wrong firmware flashes are how inverter warranty desks push back. Keep the commissioning report and NRS settings printout in the same folder as the battery registration — replacement cost · warranties.
Related answers
Grid-loss vs genuine faults
During Stage, hybrids should transfer to backup cleanly. Repeated “grid loss” spam while Eskom/metro supply is present can mean CT orientation, neutral-earth issues, or firmware. Do not keep factory-resetting; capture the event list and call the commissioning installer — solar in load shedding · changeover / ATS.