- Solar and energy
- Solar inverter
302
Growatt 302 on a solar inverter: no AC grid connection detected
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
The Growatt inverter does not detect the AC grid (No AC connection) and cannot feed in. Check that the house has power and that the inverter's breaker in the consumer unit is on. If it trips again, leave it off and call your installer.
Safety first
Stop and check this first
- If the inverter breaker trips again, do not keep switching it back on. A repeated trip signals a defect for an electrician to find.
Safe checks you can perform
- House power supply
- Inverter AC breaker status
- AC wiring check up to the inverter
Leave these tasks to a qualified professional
- Do not attempt this professional task: Voltage check at the AC terminals
- Do not attempt this professional task: Diagnosis of a tripping breaker
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Voltage check at the AC terminals
What they doMeasures grid voltage at the inverter AC input and at the breaker output in the consumer unit.
They must show youthe voltage at each point along the circuit.
In writingwhere it was interrupted and what was repaired.
Diagnosis of a tripping breaker
What they doIf the inverter's MCB or RCD trips, finds the cause in the circuit before resetting.
They must show youthe circuit and breaker test.
In writingthe cause of the trip and any part or cable replaced, with the reason.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
House power supply
- Who:
- you, no tools.
- How:
- check whether lights and sockets in the house work and whether there is a local outage.
- Result that matters:
- whether grid power is available to the inverter.
- If the house has no power:
- it is a grid outage; the inverter will reconnect when it returns.
- If the house has power:
- move on to the inverter breaker in the consumer unit.
- Evidence to keep:
- time of the outage and any network operator notice.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
Inverter AC breaker status
- Who:
- you, looking at the consumer unit without removing covers.
- How:
- find the breaker labelled for the inverter or solar and see whether it is on or off.
- Result that matters:
- whether the inverter's AC circuit is connected.
- If it was off and switching it on once lets the inverter start:
- confirms that was the cause.
- If it trips again or was already on:
- leave it and call the installer.
- Evidence to keep:
- photo of the consumer unit showing the breaker position and label.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
AC wiring check up to the inverter
- Who:
- qualified installer or electrician.
- How:
- check the AC cabling and terminals between consumer unit and inverter and verify grid voltage at the inverter input.
- Result that matters:
- grid voltage reaching the inverter's AC terminals.
- If no voltage arrives:
- the fault is in the wiring or protection devices.
- If voltage arrives and 302 remains:
- it needs to go to Growatt service.
- Evidence to keep:
- voltage reading at the terminals and photos of the AC connector.
Opening or measuring at the AC connector means working at mains voltage. Only a qualified electrician or installer does it.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Solar and energy
- Brand
- Growatt
- Product type
- Solar inverter
Known code variants
- 302 Encontrado
- 302 Found
- 302 Gefunden
- 302 Trouvé
- 302 Trovato
- código HTTP 302
- error HTTP 302
- événement Fronius 302
- événement SMA 302
- evento Fronius 302
- evento SMA 302
- Fronius Ereignis 302
- Fronius event 302
- Fronius inverter 302
- Fronius Symo / Eco 302
- Fronius Wechselrichter 302
- Growatt 302 sin conexión de red
- Growatt error 302
- Growatt Error: 302
- Growatt No AC Connection
- Growatt no grid connection
- HTTP 302
- HTTP error 302
- HTTP status 302
- inversor Fronius 302
- inversor SMA 302
- inverter Fronius 302
- inverter SMA 302
- onduleur Fronius 302
- onduleur SMA 302
- SMA Ereignis 302
- SMA event 302
- SMA inverter 302
- SMA Wechselrichter 302
- status code 302
- Sunny Tripower X 302
What it means
Growatt defines Error 302 as a system fault for no AC connection: the inverter sees no grid voltage at its output. The manual asks to check the AC wiring and the status of the AC breaker. It can come from a grid outage, a breaker that is off or tripped, or a loose AC cable or terminal between the consumer unit and the inverter. The code does not say which, and does not prove the inverter is faulty.
Warnings and stop conditions
- Mediumeditorial warning
If the inverter breaker trips again, do not keep switching it back on. A repeated trip signals a defect for an electrician to find.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
Symptoms and causes
Probable causes · in order
- AC breaker off or trippedCommon
Growatt asks to check the status of the AC breaker. If it is off, the inverter sees no grid. You can tell by looking at the consumer unit.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
- Grid power outagePossible
If the house is also without power, the inverter has no grid to connect to. It clears when supply returns.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
- Loose or damaged AC wiring or terminalsPossible
The manual asks to check the AC wiring. If the house has power and the breaker is on, a connection between consumer unit and inverter is broken.
Evidence: Installation & Operation Manual MIN 2500TL-X MIN 3000TL-X MIN 3600TL-X MIN 4200TL-X MIN 4600TL-X MIN 5000TL-X MIN 6000TL-X (GR-UM-155-A-04) · Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
Virtual technician
Does 302 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Shenzhen Growatt New Energy Co., Ltd · 2022 · manual
- 2
Installation & Operation Manual MIC 600TL-X to MIC 3300TL-X (MIC_600-3300TL-X EN 202309)
Shenzhen Growatt New Energy Co., Ltd · 2023 · manual
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