Warning What does this mean?

Your system is down or running degraded, but this is not an immediate safety danger. Work through the safe steps below.

SMA Inverter Code 1302 — When the Grid Voltage Never Arrives

Event 1302 means your SMA inverter can't detect any grid voltage at all — either line (L) or neutral (N) isn't connected, or the utility grid itself is down. SMA's messages say it plainly: 'Waiting for grid voltage,' 'Grid connection installation failure,' 'Check grid and fuses.' Check for a power outage and your solar breaker first; if the grid is up and the breaker is on, the wiring needs a professional.

What should I do first?

Two quick questions — we'll point you to the right starting point.

Is this code still showing on your inverter's display?

What this code means

Most grid-related events are about the grid misbehaving — voltage too high, frequency too low, a transient that came and went. Event 1302 is simpler and starker: as far as your inverter can tell, there is no grid at all. SMA's explanation is one line: "Either L or N is not connected, or the utility grid has failed."

Think about what the inverter needs in order to do anything. Before it can feed a single watt, it must measure the grid's voltage, confirm it's within limits, synchronize to its frequency, and run through its anti-islanding checks. Event 1302 fires before any of that — the inverter is stuck at step zero, "Waiting for grid voltage," because its terminals see nothing to synchronize to. It's not a measurement out of range; it's the absence of measurement.

That's why 1302 shows up in two different life stages. On a brand-new installation it's the classic "not commissioned yet" event — the AC cable isn't landed, the breaker isn't on, or the meter panel work isn't finished. The inverter is correctly reporting that its grid connection doesn't exist yet. On a system that used to work, 1302 means something changed: a breaker tripped or was switched off, a fuse blew, the grid went down, or a cable or connection failed.

SMA's corrective measures read like a checklist in order of likelihood: "Ensure that there is no utility grid failure. Ensure that the line conductors are connected. Ensure that the miniature circuit breaker is switched on. Ensure that the AC cable is not damaged and that it is connected correctly." Notice the progression — from things anyone can check (is the power out?) to things only a qualified person should touch (is the cable damaged?). The manual page is marked "Qualified person," and that marking applies to the back half of the list, not the front.

What is this downtime costing you?

Rough estimate while your system isn't producing. Adjust the numbers to match your setup.

System size (kW) Peak sun hours / day Electricity rate ($/kWh)

–per day

–per week

–per 30 days

≈ – kWh of lost production per day.

Estimate only — assumes ~80% real-world output vs. nameplate. Actual losses depend on weather, shading, panel direction, and your tariff.

Common causes

The solar AC breaker (miniature circuit breaker) is off or has tripped. The most common cause on a working system — sometimes switched off during other electrical work and never switched back on.
A utility grid failure. If the whole street is dark, the inverter isn't broken; it's accurately reporting that there's no grid to connect to.
Incomplete installation or commissioning. On new systems, 1302 simply means the AC side isn't finished — cable not connected, panel work pending.
A failed connection or damaged AC cable. Loose terminations, a cable damaged during other work, or corrosion over time can silently sever the inverter's grid connection.
A blown fuse in the AC path, where fuses are used in the AC path.

Safe steps to try

Work top to bottom, ticking off each step as you complete it. 0 of 5 done.

1. Check whether there's a power outage. Look at your neighbors, check your utility's outage map. No grid = no mystery; wait it out and the inverter will start itself when power returns.
2. Check your main electrical panel for the solar/PV breaker. If it's clearly labeled and switched off, switching it back on is safe homeowner territory. If it trips again immediately, leave it off — a breaker that won't stay on is protecting you from something.
3. If the system is brand new and never fed power, 1302 is almost certainly an unfinished installation step. Note it and call your installer rather than hunting through the panel.
4. Don't go beyond the breaker. Checking whether "the line conductors are connected" or whether "the AC cable is damaged" means opening panels and handling live AC wiring — that's the qualified-person part of SMA's list, not yours.
5. Note the circumstances: did 1302 appear right after a storm, after electrical work, or out of nowhere on a calm day? That context is genuinely useful to whoever investigates.

Is your inverter still under warranty?

Before paying for a repair, check — your installer may fix this free.

Brand Year installed

Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.

When to call an electrician

Call your installer if the grid is up, the solar breaker is on (and stays on), and 1302 persists — at that point the cause is in the wiring, the connections, or the cable, and every remaining item on SMA's corrective list is professional work. Call urgently if the breaker trips the moment you switch it on, or if you see any sign of heat, scorching, or burning smell at the panel or inverter — switch the breaker off, keep clear, and get a professional out. For new installations showing 1302, the installer owns the resolution from the start: it's their commissioning checklist, not yours.

Frequently asked questions

Does 1302 mean my inverter is broken?

Very unlikely. 1302 means the inverter sees no grid voltage — the problem is upstream of the inverter (breaker, outage, wiring), not inside it.

My whole street has power, but I have 1302. What now?

Check your solar breaker first. If it's on and the grid is fine, the fault is in your AC connection — loose conductors, a damaged cable, or a failed connection — and your installer needs to investigate.

The system is brand new and has never produced. Is 1302 normal?

It's expected, not normal — it means the AC side isn't commissioned yet. Your installer needs to complete the grid connection and commissioning.

Can I check the AC cable myself?

No. SMA's corrective measures list cable and connection checks, but the page is marked for qualified persons — that work involves live AC wiring. The breaker check and the outage check are yours; everything past the breaker is theirs.

Will the inverter recover on its own after an outage?

Yes. Once grid voltage returns and holds steady through the inverter's monitoring period, it reconnects and resumes feeding automatically.

Need a professional?

This fault may need professional diagnosis. Contact a qualified solar electrician in your area.

Sources: meaning and troubleshooting verified against the manufacturer's documentation — SMA Sunny Boy / Sunny Boy Smart Energy operating manuals (manuals.sma.de) — Troubleshooting, Event messages: Event 1302 (messages: 'Waiting for grid voltage' / 'Grid connection installation failure' / 'Check grid and fuses'; explanation: either L or N is not connected, or the utility grid has failed; corrective measures: rule out grid failure, verify line conductors connected, MCB switched on, AC cable undamaged and correctly connected)