If your microwave turns off automatically after being used for a while, even when there's no food inside, it is likely due to a safety feature known as a "microwave oven safety cut-off" or "thermal cut-off." This safety feature is designed to protect the microwave from overheating and prevent potential hazards.
Here's how the microwave oven safety cut-off works:
Overheating Protection: Microwaves generate heat to cook or heat food. During the cooking process, the microwave's magnetron (the component responsible for producing microwaves) can become very hot. If the microwave is operated without any food or liquid inside, the magnetron can heat up excessively, potentially causing damage to the microwave's internal components.
Thermal Sensor: To prevent overheating, modern microwaves are equipped with a thermal sensor. This sensor monitors the internal temperature of the microwave while it is in operation. If the temperature rises beyond a certain safe threshold, the thermal sensor triggers a safety cut-off.
Automatic Shut-Down: When the thermal sensor detects excessive heat, it activates the safety cut-off, which automatically turns off the microwave to cool down the internal components and prevent further overheating.
Resetting: After the microwave cools down and the internal temperature drops to a safe level, the safety cut-off is reset, and you can use the microwave again.
The automatic shut-off can also be triggered if the microwave's ventilation system is blocked or not functioning correctly, causing heat to build up inside the appliance.
If your microwave is turning off automatically without any food inside, it's likely a normal operation of the safety feature. To prevent this from happening, avoid running the microwave empty for extended periods, as this can lead to overheating. If the microwave seems to be shutting off too frequently or if you notice any other unusual behavior, it's a good idea to have it checked by a qualified technician to ensure it's functioning properly and safely.