- Solar and energy
- Solar inverter
300
Growatt 300 on a solar inverter: grid voltage out of range
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
The Growatt inverter sees the grid voltage outside the permitted range (AC V Outrange) and stops feeding in. Note the code and time each time it appears and pass it to your installer, who needs to measure the grid voltage.
Safety first
Stop and check this first
- Do not change the country or grid settings yourself to clear the alert. Voltage limits depend on the local standard and changing them is the installer's job.
- A 300 on its own does not prove the inverter is faulty: Growatt classes it as a system fault. Ask for the voltage measurement before accepting a replacement.
Safe checks you can perform
- Code and how often it appears
- House supply
- Voltage measurement and AC wiring check
Leave these tasks to a qualified professional
- Do not attempt this professional task: Neutral, earth and country setting check
- Do not attempt this professional task: Grid voltage measurement at the connection point
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.
Neutral, earth and country setting check
What they doChecks tightness and condition of neutral and earth on the AC side and the grid standard selected in the inverter.
They must show youphotos of the terminals and the screen with the configured country.
In writingwhat was corrected and that the inverter started afterwards.
Grid voltage measurement at the connection point
What they doMeasures grid voltage at the inverter terminals and the consumer unit, ideally at the times the code appears.
They must show youmeasured values against the local standard's range.
In writingvalues, time of measurement and conclusion.
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.
Code and how often it appears
- Who:
- you, no tools.
- How:
- look at the OLED screen or the app and write down the exact text, AC V Outrange or Error: 300, with date and time.
- Result that matters:
- how often it appears and at what times.
- If it is rare and the inverter recovers on its own:
- points to short grid variations.
- If it repeats daily or at the same times:
- the grid voltage at your installation needs measuring.
- Evidence to keep:
- screen photos and a list of dates and times.
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)
House supply
- Who:
- you, looking at the consumer unit without opening it.
- How:
- check whether the rest of the house has power and whether there were outages or flicker when the code appeared.
- Result that matters:
- whether the issue is the general grid or only the inverter.
- If there were outages or flicker at the same time:
- points to the grid; tell the installer and the network operator.
- If the house works normally:
- it does not rule out the grid, but the installer must measure at the connection point.
- Evidence to keep:
- notes of outages or network operator notices.
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)
Voltage measurement and AC wiring check
- Who:
- qualified installer or electrician.
- How:
- following the manual, switch off the DC side, check the AC wiring with attention to neutral and earth, and measure grid voltage at the connection point.
- Result that matters:
- measured voltage against the range of the configured local grid standard.
- If voltage is out of range:
- it is a grid problem; the network operator must look at it.
- If voltage is in range and wiring is fine:
- check the configured standard and, if it persists, Growatt says to contact its service.
- Evidence to keep:
- measured values with time and photos of the AC terminals.
Measuring grid voltage and opening AC wiring means working near dangerous 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
- 300 Choix multiples
- 300 Mehrere Auswahlmöglichkeiten
- 300 Multiple Choices
- 300 Múltiples opciones
- 300 Scelte multiple
- Growatt 300 tensión de red fuera de rango
- Growatt AC V Outrange
- Growatt error 300
- Growatt Error: 300
- Growatt grid voltage out of range
- HTTP 300
- HTTP status 300
What it means
Growatt lists this among system faults: the utility grid voltage is outside the range permitted by the configured grid standard. The manual points to the grid itself, the AC wiring, especially neutral and earth, and whether the voltage complies with the local grid standard. So the code does not point to a faulty inverter part: it can come from the distribution grid, a loose connection or a country setting that does not match.
Warnings and stop conditions
- Mediumeditorial warning
Do not change the country or grid settings yourself to clear the alert. Voltage limits depend on the local standard and changing them is the installer's job.
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)
- Loweditorial warning
A 300 on its own does not prove the inverter is faulty: Growatt classes it as a system fault. Ask for the voltage measurement before accepting a replacement.
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
- Grid voltage outside the standard's rangeCommon
This is the manufacturer's definition: utility grid voltage out of permissible range. If neighbours see it too or it happens at set times, it points to the distribution grid.
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)
- Faulty AC wiring, neutral or earthPossible
Growatt asks to check the AC wiring, especially neutral and earth. A loose connection makes the inverter see a voltage different from the real grid.
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)
- Wrong country or grid standard settingPossible
The inverter applies the limits of the country selected at start-up; if none is chosen it uses a default standard. A setting that does not match your grid can give a 300 at normal voltage.
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 300 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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