Refrigeration Quiz - 10 Questions

A relay on a refrigerator is responsible for starting the compressor. The compressor is an essential component that circulates refrigerant throughout the system, allowing the refrigerator to cool and maintain a desired temperature. The relay acts as a switch, sending an electrical signal to the compressor to initiate its operation. Without the relay, the compressor would not start, and the refrigerator would not be able to cool properly.

When a refrigerator is running, the refrigerant in the condenser is in a state of high pressure vapor/liquid. This is because the condenser is responsible for releasing heat from the refrigerant, causing it to condense from a high pressure vapor to a high pressure liquid. The high pressure is necessary for the refrigerant to effectively transfer heat and maintain the cooling process in the refrigerator.

When a refrigerator is running, the state of refrigerant in the evaporator is a low pressure vapor/liquid. This is because the evaporator is responsible for absorbing heat from the refrigerator's contents, causing the refrigerant to evaporate and turn into a low pressure vapor. However, there may still be some liquid refrigerant present in the evaporator as well. Therefore, the correct answer is low pressure vapor/liquid.

The correct answer is Defrost Timer. The defrost timer is a component in a refrigerator or freezer that controls the automatic defrost cycle. It regulates when the defrost heater turns on to melt any ice buildup on the evaporator coils, preventing them from becoming blocked and ensuring efficient cooling. The defrost timer typically operates on a set time schedule, activating the defrost cycle at regular intervals.

The correct answer is to check for the appropriate resistance based on temperature, as each thermistor model has a specific resistance value at different temperatures. By measuring the resistance of the thermistor, one can determine if it is functioning properly and accurately sensing temperature changes.

The purpose of the defrost cycle is to remove frost from the evaporator. During normal operation, moisture in the air inside the freezer can condense on the evaporator coils and freeze, forming a layer of frost. This frost can reduce the efficiency of the freezer and prevent proper cooling. The defrost cycle activates periodically to melt this frost, allowing the evaporator coils to operate efficiently and maintain proper cooling temperatures.

The statement is false because defrost bi-metals are not universal and cannot fit into any model or brand. Different models and brands may have different specifications and requirements for their defrost systems, including the type and size of the bi-metal used. Therefore, it is important to select a defrost bi-metal that is specifically designed and compatible with the model or brand of the appliance.

The correct answer is "Positive Temperature Coefficient." In regards to a PTC relay, PTC stands for Positive Temperature Coefficient. This refers to a type of relay that uses a temperature-sensitive resistor to control the flow of current. As the temperature increases, the resistance of the PTC relay also increases, causing the current to decrease. This characteristic makes PTC relays useful for protecting electrical circuits from overheating and overcurrent situations.

To test a PTC relay, one should check the resistance between the start and run terminals. The resistance should ideally measure between 4 to 10 ohms. This test helps determine if the PTC relay is functioning properly.

Vaseline is commonly used as a lubricant for door gaskets because it is a thick, petroleum-based jelly that helps to reduce friction and keep the gaskets flexible. Applying a thin film of Vaseline on the hinge side of the door gaskets can help to prevent them from sticking or squeaking when the door is opened or closed. The viscosity of Vaseline allows it to stay in place and provide long-lasting lubrication.