Inverter Repair After a Voltage Surge – What Can Be Saved and What Needs Replacing

Industrial inverters and solar PV inverters are particularly exposed to voltage surges – from the mains supply as well as lightning strikes hitting the installation. The result is usually damage to IGBT modules, gate driver circuits or input filters.

Symptoms of surge damage

• The inverter won't power on, the status LED stays off.
• An overcurrent or output short-circuit error code.
• It powers on briefly, then trips on overcurrent protection.
• A damaged fan or blown internal fuses.

What can be repaired

In most cases a surge damages specific components – IGBT modules, gate drivers, filter capacitors or voltage sensing circuits. Replacing the damaged components, rather than the whole inverter, is possible in many cases and significantly reduces the cost compared to buying a new unit.

When repair isn't worth it

If the surge caused extensive damage across multiple circuits at once (e.g. the entire power and control section), repair cost can approach that of a new unit. That's why we always start with diagnostics and provide a quote before starting repair.

Protecting the installation going forward

Consider surge protection devices (SPDs) at the power input and on the DC side of a solar installation – this significantly reduces the risk of another failure after a storm.

Get in touch

We diagnose and repair industrial and solar inverters from Fronius, SMA, ABB and Danfoss. Call +48 504 511 170 and describe the fault.