Inverter cooling is the way an inverter gets rid of the heat its power electronics produce while it runs. Datasheets usually list it as one of two methods: natural convection with no fans, or forced air from fans that may be variable speed or temperature controlled. Microinverters and many string inverters use natural convection. Larger string, hybrid and central inverters often use fans that help the convection. Large central inverters can use a sealed internal air loop that passes its heat to a filtered external air stream through an air-to-air heat exchanger. The hottest parts, such as the sine filter choke, are cooled last. If cooling cannot keep up, for example because a fan has failed, a filter is clogged, ambient heat is high or the site is at high altitude, the inverter derates and limits its output to protect its semiconductors. High internal temperature or abnormal fan noise with clean, unblocked vents points to a fan that needs replacing. At installation, leave the required clearances at the sides and top and avoid direct sunlight, or the inverter may overheat.
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explainsc1 drafted · lead Thermal derating
When cooling cannot remove enough heat, the inverter limits its maximum output power to protect semiconductors and other components; a failed fan also curtails output.
sec=h1 h=29bb5fd6708csec=7.1 h=dccb778213f0sec=7.1 h=5f864ecd896brelated_toTemperature derating is a protective state, not an error; it can be triggered by ambient temperature or internally measured temperatures.
sec=h1 h=29bb5fd6708cc3 drafted · lead Cooling fan
sec=7.1 h=dccb778213f0sec=7.1 h=5f864ecd896bsec=h164 h=43fdc21af7d8tbl=69.r8 h=433c7c29e91etbl=2.r44 h=9e729a9cbfd7In the Sunny Central design, the IGBTs are cooled indirectly through cooling fins that reach into the external air channel.
sec=h1 h=29bb5fd6708cverified by: review-workflowverified on: 2026-10-24
c5 drafted · lead Fan failure
sec=7.1 h=dccb778213f0sec=7.1 h=5f864ecd896bsec=h152 h=b00a0e7d3b15sec=h214 h=b00a0e7d3b15c6 verified · fact Inverter Overheating
Incorrect installation that does not leave cooling clearances can cause the inverter to overheat.
tbl=52.r5 h=46c42be6ee70verified by: review-workflowverified on: 2026-10-24
c7 drafted · lead Minimum installation clearances
Leave gaps at both sides and at the top so the inverter can cool properly.
tbl=52.r5 h=46c42be6ee70c8 drafted · lead Direct sunlight avoidance
tbl=52.r5 h=46c42be6ee70c9 drafted · lead Fan replacement
sec=7.1 h=dccb778213f0sec=7.1 h=5f864ecd896bsec=h164 h=43fdc21af7d8c10 verified · fact Clear ventilation blockage
If internal overtemperature derating occurs while ambient temperature is not critical, the cooling filters may need cleaning.
sec=h1 h=29bb5fd6708csec=h164 h=43fdc21af7d8verified by: review-workflowverified on: 2026-10-24
c11 drafted · lead High inverter internal temperature
sec=h164 h=43fdc21af7d8c12 drafted · lead Abnormal fan noise
sec=h164 h=43fdc21af7d8c13 drafted · lead High altitude
Thinner air at high altitude cools less well, so derating starts earlier and is steeper.
sec=h1 h=29bb5fd6708cc14 verified · fact High operating temperature
sec=h1 h=29bb5fd6708cverified by: review-workflowverified on: 2026-10-24
related_to c3