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.

Growatt Inverter Error 122: Meaning, Causes & Safe Fix

Error 122 means the inverter's internal DC bus voltage is out of range — often linked to the solar panel input voltage being too high or too low for the inverter's limits.

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

The DC bus is the internal high-voltage stage that converts your panels' DC into grid-ready AC. Error 122 means this bus voltage has drifted outside its permitted range, so the inverter shuts down to protect itself.

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

PV string voltage above the inverter's maximum DC input (too many panels in series)
PV voltage below the operating range
Internal bus capacitor or voltage-sensing fault

Safe steps to try

Work top to bottom, ticking off each step as you complete it. 0 of 4 done.

Note the error and check the display for the PV voltage reading if shown.
Perform one restart: AC breaker off, DC switch off, wait 2–3 minutes, DC switch on, then AC breaker on.
If the error appeared on a very cold, bright morning, note that — cold panels produce higher voltage.
Do NOT add, remove, or rewire panels yourself.

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 Error 122 persists — especially if the PV voltage exceeds the inverter's maximum DC rating on its datasheet, the string may need rewiring (fewer panels per string), which is strictly an installer job. If voltages look normal but the error persists, contact Growatt service.

Frequently asked questions

Can cold weather cause Error 122?

Yes — solar panels produce higher voltage when cold. On a freezing bright morning, a string that is fine in summer can briefly exceed the inverter's limit.

How do I know my PV voltage?

Many Growatt inverters show it on the display (look for a PV voltage readout). Compare it to the 'max DC voltage' on your inverter's datasheet or nameplate — but do not touch any wiring.

Is Error 122 dangerous?

The inverter protects itself by shutting down. The risk is to the equipment, not to you — but the fix (changing panel wiring) must be done by a professional.

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 — Troubleshooting for Growatt TL&MTL (Ver1.2) 2013-7-15, Growatt New Energy ('it means the Bus voltage is out of range')