Reading Your Inverter Fault Codes

Inverter fault codes are the system telling you what’s wrong before you spend money diagnosing it. Most owners ignore them because the documentation is buried in a 200-page installation manual. This guide gives you the codes that matter on the four inverter brands most common in Gold Coast installs (Fronius, SMA, Sungrow, and GoodWe) and what each one actually means.

Fronius

Fronius categorises faults by prefix. The prefix tells you who owns the problem.

Prefix	Meaning	Who fixes it
State 102, 103, 105, 107	Grid-side voltage or frequency outside tolerance	Usually self-clears. Repeated occurrence is a DNSP issue, not the inverter.
State 301, 302, 303	DC string fault, voltage or current outside expected range	Solar electrician. String testing required.
State 401–406	Internal communication fault	Often resolves with a power cycle. Persistent: service call.
State 501–509	Insulation resistance fault	Solar electrician. DC isolation issue, not safe to leave running.
State 567	Grid voltage too high. Inverter disconnected to protect itself.	Common on Queensland summer afternoons. DNSP issue if it persists.

The full Fronius event list is published in the Fronius Symo / Primo Operating Instructions available from fronius.com under support. Fault history is also visible in Solar.web. Log in, select your system, and the events tab shows everything the inverter has logged.

What “State 567” really means

This one trips up a lot of Gold Coast owners. The Australian standard says inverters must disconnect when grid voltage exceeds 253V (which is 230V +10%). Queensland summer afternoons routinely push neighbourhood voltage above this because everyone’s solar is exporting at once.

The inverter isn’t broken. The grid is over-voltage. There are three real fixes, none of them DIY:

1. Reduce the inverter’s export limit (DNSP-approved volt-watt response)
2. Add battery storage so excess production goes to the battery instead of the grid
3. Have the DNSP investigate the local feeder voltage

Replacing the inverter does nothing. A new one will trip on the same code.

SMA

SMA uses event numbers. The Sunny Portal shows them in plain language but the underlying number tells you what to look up.

Event	Meaning	Action
101, 102, 103	Grid voltage or frequency fault	Self-clearing if intermittent. Persistent: DNSP issue.
301, 302	Grid disconnection due to anti-islanding	Normal during grid events.
501	Insulation fault	Stop using until investigated. DC side issue.
601, 602	DC overvoltage	String oversized or temperature-correction wrong
1302, 1303, 1304	Earth fault current too high	Solar electrician required
3301, 3302	Internal hardware fault	Manufacturer service call
6001–6499	Internal communication errors	Usually self-clears. Persistent: service call.
7702, 7703	Firmware update failed	Repeat the update with stable network connection

SMA Sunny Portal shows the event log under each plant. The SMA Event Messages and Corrective Measures document is publicly available on the SMA website and lists every code with the recommended action.

Sungrow

Sungrow uses error codes prefixed with the letter E for errors and W for warnings.

Code	Meaning	Action
E001–E010	Grid-side voltage or frequency fault	Self-clearing
E020, E021	DC overvoltage / undervoltage	Check string sizing and panel performance
E030, E031	Insulation impedance low	Stop using. DC isolation fault.
E040	Earth fault current high	Solar electrician required
E050	Internal temperature too high	Check ventilation, shade the inverter, clean fan filters
E090	Anti-islanding triggered	Normal during grid disconnection
W001–W010	Warnings. System continues operating but log for follow-up.	Usually doesn’t require immediate action

Sungrow’s iSolarCloud app displays these codes. The Sungrow Fault and Alarm Code List is downloadable from the Sungrow service portal.

GoodWe

GoodWe uses a numeric system documented in their GoodWe Inverter Error Code List.

Code	Meaning	Action
02	Grid voltage fault	Self-clearing
03	Grid frequency fault	Self-clearing
09	Isolation resistance low	DC fault. Solar electrician.
10	Earth current high	Solar electrician
11	DC injection fault	Internal. Service call.
14	Inverter over-temperature	Check ventilation
17	DC overvoltage	String configuration check
23	Internal communication fault	Power cycle, then service call if persistent

The SEMS Portal (GoodWe’s monitoring platform) logs these against your system. If the SEMS Portal isn’t showing recent data, that itself is a warning. Your monitoring may have lost connection, even if the inverter is still producing.

How to find the code

Three places to look:

1. The inverter screen. Most inverters cycle through current status, today’s production, and any active fault. If the screen is blank, the inverter has lost AC supply or DC supply. That’s its own diagnostic.
2. The monitoring app or portal. Solar.web, Sunny Portal, iSolarCloud, SEMS Portal. The fault history is usually under an “events” or “alarms” tab.
3. The installation paperwork. Your original handover should have included the inverter’s serial number, monitoring login, and the manufacturer’s service contact.

If the monitoring app shows historical data but stops at a specific date, that’s your fault date. Compare that to weather, grid events, or any work done on the property around that time.

What you can fix yourself

Almost nothing on the inverter itself. AS/NZS 4777 grid-connection rules require that any work on the AC or DC side of an inverter is done by a person holding the appropriate licence. You can:

• Power cycle the inverter (turn AC isolator off, wait 30 seconds, turn back on). This clears most communication faults.
• Reset the Wi-Fi connection if the monitoring data has stopped
• Clear panel surfaces of leaves, dust, or bird droppings
• Note the fault code and timestamp before calling for service

You cannot legally:

• Open the inverter
• Test or replace DC components
• Modify any wiring
• Replace the inverter

When the code says it’s the grid, not the inverter

Several of the codes above are flagged as “self-clearing” or “DNSP issue.” That’s because the inverter is correctly protecting itself from a grid problem. Replacing the inverter doesn’t fix the grid. If you’re getting repeated voltage-related disconnects, the right call is to your electricity distributor (Energex on the Gold Coast) to investigate the local feeder, not to your installer for a new inverter.

A Solar Health Check includes log review on the inverter, voltage testing on the AC supply, and a written report you can use to escalate to Energex if needed.

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