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SolarEdge inverter keeps restarting or failing with a voltage or 18xB code
Your SolarEdge inverter keeps restarting, or fails again and again, and shows a voltage message or a code such as 18xB5. This page covers what the lights and codes mean, what to check first, and the causes behind it.
What the lights mean
| What you see | What it means |
|---|---|
| Flashing green light | The manual describes it as overheating, but it has turned out to be an 18xB5 code in the error log. Read the code as well as the light. |
| Flashing green and flashing blue | AC is connected but the inverter is not producing, and its link to monitoring comes and goes. |
| Solid green and solid blue | Producing normally and connected to monitoring. After a full restart it can take up to five minutes to get here. |
Error codes that go with this problem
| Code | What it means |
|---|---|
| 18xB5, 18xB7 or another code starting 18xB | SolarEdge's error-code guide lists these as overvoltage inside the inverter or power module voltage imbalance, marked Contact Support, RMA related. Some show as a surge. |
| 18x14, 18xA5, 18xBE or 18xD6 in the error log | Error log entries such as Inv. Power Error, Tz Over current and Swing Rdiff Overheat, logged along with surge codes. SolarEdge's error-code guide does not list these exact codes. |
| 18x7B, voltage too high, or ac production is too high | 18x7B was described as grid voltage too high. These messages come and go, and production stops or the inverter restarts while they show. |
| DC voltage not safe! Do not disconnect! | Shown right before the inverter restarts. It can repeat every five minutes on a newly activated inverter. |
| 18x1C or 8x1C | Line or grid voltage is low. SolarEdge's guide says to check the inverter is set to the correct country and consult the grid operator. |
| 8x7B, 8x7C or 8x56 | SolarEdge's guide for three phase inverters lists 8x7B and 8x7C as over current and 8x56 as power train error, all marked Contact Support RMA. |
| 8x38 | AC grid voltage malfunction. SolarEdge's guide says the inverter should restart once AC voltage returns, and to consult the grid operator if it persists. |
| 8x3F, 8x40 or 8x41 | Logged in a run of over current codes alongside 8x7B and 8x7C. SolarEdge's error-code guide does not list these exact codes. |
What to check first
- Write down the exact code or message on the inverter screen, and whether the inverter restarts every few minutes or at random through the day.
- Note whether the restarts began within days of the system being switched on, and whether this inverter is a replacement for one that failed before.
- If you have two inverters, note whether one produces normally while the other shows voltage too high.
- You can try a full restart: AC disconnect, inverter switch and DC switch off for several minutes, then back on. Allow up to five minutes for the lights to go solid green and solid blue. With an 18xB code a restart has not cleared it.
- If the code comes back or the restarts continue, call your installer and pass on the code and what you noted.
Safety. If the screen says DC voltage not safe! Do not disconnect!, do not disconnect anything while it shows. The inverter is only safe to service once its DC voltage has fallen below 50 volts.
The causes and the fixes
Partners see the causes behind this problem, most common first, the checks that tell them apart, and the fix for each, with part numbers and recent prices when a part is involved.