Solar Lattice

FailureMode

Inverter Overheating

ID
fm:inverter-overheating
IRI
https://solarlattice.org/kb/fm/inverter-overheating
Status
active
Also known as
PVFS 4-1, temperature derating
Category
Inverters

Inverter overheating happens when parts inside the inverter get too hot, so the inverter cuts its power or shuts off to protect itself. This is called temperature derating. Common causes are poor installation, a failed fan, dust blocking the cooling path, or wrong inverter programming. Output drops in steps while the parts are hot, the inverter may switch off completely, and it goes back to normal operation once it cools down. The inverter does not always report a derating or power reduction status, so plot its power against irradiance in the monitoring data to see the behaviour. IV curve tracing and infrared thermography can help as well. If the inverter does not report its own temperature, add a temperature sensor to the enclosure to catch overheating. Once you find the cause, repair it and clear the filters and the cooling path of anything blocking them. To prevent it, follow the installation procedure, use adequate cooling and inspect the ventilation units regularly. The losses get worse if the problem is left alone, but this fault does not affect module safety.

Claims

affects

c1 verified · fact Inverter

verified by: joshuahamsaverified on: 2026-10-20

caused_by

c2 drafted · lead Installation error

Improper installation of the inverter

c3 drafted · lead Cooling fan failure

c4 drafted · lead Dust accumulation

Dust blocking the inverter heat dissipation path

c5 verified · fact Inverter parameter settings

Incorrect programming of the inverter

verified by: joshuahamsaverified on: 2026-10-20

presents_as

c6 drafted · lead Inverter power derating

Power reduced step by step once monitored components reach maximum operating temperature; may happen without a derating status message

c7 drafted · lead Inverter shutdown

In the extreme case the inverter switches off completely

detected_by

c8 drafted · lead Performance monitoring

c9 verified · fact Power vs irradiance analysis

Recommended because inverters do not always report a derating status

verified by: joshuahamsaverified on: 2026-10-20

c10 verified · fact IV curve tracing

Listed as a secondary detection method

verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - IV is listed in parentheses after MON, but the passages do not explicitly say it is secondary.

c11 drafted · lead Infrared thermography

Listed as a secondary detection method

review note: support check: partial - IRT is listed in parentheses after MON, but the passages do not explicitly say it is secondary.

mitigated_by

c12 drafted · lead Clear ventilation blockage

Clear filters and the heat dissipation path of obstructions

c13 drafted · lead Root cause investigation

Identify the origin of the derating, then repair it

c14 drafted · lead Proper installation

Follow the given installation procedure

c15 drafted · lead Adequate inverter cooling

c16 drafted · lead Regular system inspections

Regular inspection of the ventilation units

c17 drafted · lead Inverter temperature monitoring

Add an enclosure temperature sensor if the inverter does not report its temperature

Referenced by

Data