Inverter status codes

"A code on the inverter" usually means one of two fairly different things. Telling them apart is worth the effort, because they carry different weight.

• A status code is a short list of operating modes — running, waiting, self-testing, faulted. There are only a handful and they have a fixed meaning for a given brand.
• An error code is the specific defect within that state — DC overvoltage, an insulation fault, overheating. Every brand has dozens to hundreds of them, and the numbering differs not only between brands but between model ranges.

This article is about status codes, because they're the ones that support a reliable conclusion without knowing the exact model.

The table, using SolaX as the example

Slunora can read one brand so far, so the concrete numbers are its. The table comes from the official SolaX Cloud User API V2.0 documentation, appendix 8.1 "Device Status Mapping".

These numbers are SolaX's, not universal. Another brand may mean something entirely different by the same number. What does hold across brands is the split into those three classes — normal operation, recoverable fault, permanent fault — and that's the part anyone can use.

A recoverable fault

The inverter hit a condition under which it may not or cannot operate, disconnected, and will try again. Most often the cause is outside your system: grid voltage or frequency left the permitted range and the protection did exactly what it's meant to do.

The practical consequence: a one-off occurrence is no reason to call anyone. What's interesting is how often it happens. A recurring recoverable fault means either persistently poor grid parameters at your location, or equipment heading towards something worse.

That's why, on connected systems, we don't look only at the latest reading but also at how many readings caught the fault — "3 out of 12" says something different from "1 out of 12".

A permanent fault

This one the inverter won't resolve by itself. While it lasts, the system very probably isn't producing, and it's a case for service — not for waiting to see whether it clears.

In our diagnostics it's the only rule based on instantaneous data allowed to reach the highest severity. Other findings are inferred from production and we admit alternative explanations for them; here the device itself says it has a problem.

What a code won't tell you

And here's the boundary it's honest to admit:

• A status code gives the type of fault, not the cause. "Permanent fault" doesn't distinguish a failed power stage from an insulation fault on the roof. For that you need the error code from the inverter display or the manufacturer's app.
• It won't say how long it's been going on. From a single reading you can't tell whether the fault started an hour ago or a month ago.
• Zero output doesn't automatically follow. An inverter can report a fault and still work in a limited mode.

An unknown code

Code tables grow with new models and firmware. When a code arrives that isn't in our table, we do one of the few things that can be done honestly: we show it and say we can't translate it.

Inventing a meaning would be worse than silence — the owner would get false certainty. Hiding it isn't right either: it may help them on the phone with service, and it shows us a gap to fill. Such a finding therefore carries the lowest confidence and isn't flagged as a problem.

And the battery

The battery reports its own state separately, and the list is short: 0 normal, 1 fault, 2 disconnected.

The difference between one and two matters in practice. A disconnected battery often means a tripped breaker or broken communication between battery and inverter — typically after a power cut. The system keeps producing, it just stores nothing, so everything you don't use right away goes to the grid. You won't see it in production figures; you will see it on the electricity bill.

A fault (code 1) is reported without saying which — that again needs the battery's error code from the manufacturer's app. It's often thermal.

Why we treat this as the most certain finding

Most diagnostics works by comparing measured output against a model and drawing a conclusion from the gap. That's useful, but it always leaves room for another explanation — weather, shade, a mistyped system size.

With a status code there is no such room. The device isn't reporting an inference, it's reporting its own state. That's why it's the only kind of finding we mark as high confidence, and why it appears first in the report.

Where to find the code

1. On the inverter display — if it has one; usually the quickest route.
2. In the manufacturer's app, typically under device detail or the event log.
3. In your Slunora report, if you've connected the inverter — we pass the code through as it arrived, with the time of the reading.

When you call service, have it to hand. It halves the length of the call.

Related reading: your inverter isn't producing walks the whole path from zero output to what to tell service.