How hot do Hoymiles HTM 2250 microinverters typically reach in direct sunlight under a panel
When mounted under a solar panel, the Hoymiles HTM 2250 microinverter is typically shielded from direct sunlight, but still exposed to substantial heat from both ambient temperature and radiant energy from the panels themselves. The manufacturer specifies an operational ambient temperature range of
-40°C to 65°C
. Because electronic components generate additional heat internally, under high-load and hot ambient conditions, the internal temperature of microinverters can exceed the ambient by
10–20°C.
- In field reports and reviews, Hoymiles microinverters have been recorded reaching internal temperatures of up to 77°C even in conditions that are not extreme (e.g., moderate spring temperatures, tilted installations)
- . If placed directly in sunlight (i.e., not shaded by the panel), surface and internal temperatures can increase further.
- However, under a panel in full summer sun (i.e., not fully exposed to direct overhead sunlight but still in a warm, low-airflow environment), typical cases result in surface or internal temperatures often ranging from 50°C up to near the thermal derating threshold: about 65–75°C at the hottest periods of the day
- If the microinverter temperature approaches 75°C, thermal derating mechanisms will reduce output; if it approaches 80°C, the device will initiate thermal shutdown to protect itself