The power goes out in a microwave or oven when you open the door while it's running due to a safety feature called an interlock switch or door switch. This safety mechanism is designed to prevent accidental exposure to microwave radiation or high heat when the door is open.
When the microwave or oven is running, the interlock switch is engaged, and it interrupts the power supply to the magnetron (in the case of a microwave) or the heating elements (in the case of an oven). The magnetron is responsible for generating microwave radiation, and the heating elements produce high heat for cooking. When the door is opened, the interlock switch disengages, cutting off the power to these components, ensuring that they stop functioning immediately.
On the other hand, when the microwave or oven is off and plugged into the socket, the interlock switch is not engaged. As a result, the power is not interrupted, and the appliance remains connected to the electrical supply without any safety features preventing it from being active.
The interlock switch is a critical safety feature that helps protect users from potential harm, such as burns or exposure to microwave radiation. It is essential always to follow the manufacturer's guidelines and avoid tampering with the interlock switch or using an oven or microwave with a faulty door mechanism. If you notice any issues with the door or interlock switch, it's best to have the appliance inspected and repaired by a qualified technician to ensure safe operation.