This schematic represents a comprehensive wiring diagram of a frost-free refrigerator system, integrating both cooling and defrosting functionalities. The power supply is connected through Line (L), Neutral 👎, and Earth (E), distributing current to all components. The thermostat regulates the cooling cycle by controlling the compressor via the relay and overload protector, which are wired to the compressor terminals: Common (C), Start (S), and Run (R). The defrost system includes a defrost timer, defrost thermostat, defrost heater, and a thermo fuse to manage and protect the heating elements during defrost cycles. A fan motor circulates cold air throughout the refrigerator. The door switch controls the internal light bulb, ensuring it operates only when the door is open. This integrated wiring layout ensures automatic operation, energy efficiency, and protection of the refrigeration system under varying load and temperature conditions.

This no‑frost refrigerator schematic integrates both the electrical control and refrigeration circuits into a single system: 220 VAC mains power enters the unit and, via the thermostat, energizes the compressor’s start relay and overload protector to drive the hermetic compressor. The compressor pressurizes refrigerant to the condenser coils, where heat is rejected before the liquid refrigerant passes through a capillary tube and filter into the freezer evaporator; an evaporator fan then circulates cold air. Simultaneously, a defrost timer cycles power to the defrost heater—protected by a thermal fuse and monitored by a defrost thermocouple—to periodically melt frost buildup, while a cabin light and evaporator fan maintain interior illumination and airflow. All components are interlinked by the defrost timer and thermostat to ensure efficient cooling, automatic defrost, and safe operation.