Refrigeration System

Combustibility of HFC-134a

HFC-134a is nonflammable at ambient

temperatures and atmospheric pressure. However, tests have shown HFC-134a to be combustible at pressures as low as 5.5 psig (139.3 kPa absolute) at 177°C (350°F) when mixed with air at concentrations generally greater than 60% volume air. At lower temperatures, higher pressures are required for combustibility. (HCFC-22 is also combustible at pressures above atmospheric in the presence of high air concentrations). Test results and calculations have shown:

•At ambient temperature, all concentrations of HFC-134a in air are nonflammable at pressures below 15 psig (205 kPa absolute).

•Combustible mixtures of air and HFC-134a will not form when liquid HFC-134a is pumped into closed vessel if initial air pressure in vessel is limited to one atmosphere absolute and final pressure is limited to 300 psig (2,170 kPa absolute). If initial air pressure is greater than one atmosphere, combustible mixtures may form as tank is filled.

Based on above information, the following operating practices are recommended:

Leak Testing

•Equipment should NEVER be leak tested with a pressurized mixture of HFC-134a and air. HFC-134a may be safely pressured with dry nitrogen.

Bulk Delivery and Storage

•Tanks should normally be evacuated at start of filling, and should never be filled while under positive air pressure.

•Tank pressure should never be allowed to exceed 300 psig (2,170 kPa) when filling with HFC-134a. Relief devices on either tanks or HFC-134a supply system usually prevent this.

•Tank pressures should be monitored routinely.

•Air lines should never be connected to storage tanks.

Filling and Charging Operations

•Before evacuating cylinders or refrigeration equipment, any remaining refrigerant should be removed by recovery system.

•Vacuum pump discharge lines should be free of restrictions that could increase discharge pressures above 15 psig (205 kPa) and result in formation of combustible mixtures.

•Cylinders or refrigeration equipment should normally be evacuated at start of filling, and should never be filled while under positive air pressure.

•Final pressures should not exceed 300 psig (2,170 kPa).

•Filled cylinders should periodically be analyzed for air (nonabsorbable gas or NAG).

Refrigerant Recovery Systems

Efficient recovery of refrigerant from equipment or containers requires evacuation at the end of the recovery cycle. Suction lines to a recovery compressor should be periodically checked for leaks to prevent compressing air into the recovery cylinder during evacuation. In addition, the recovery cylinder pressure should be monitored, and evacuation stopped in the event of a rapid pressure rise indicating the presence of noncondensable air. The recovery cylinder contents should then be analyzed for NAG, and the recovery system leak checked if air is present. DO NOT continue to evacuate a refrigeration system that has a major leak.

Thermal Decomposition

HFC-134a vapors will decompose when exposed to high temperatures from flames or electric resistance heaters. Decomposition may produce toxic and irritating compounds, such as hydrogen fluoride. The pungent odors released will irritate the nose and throat and generally force people to evacuate the area. Therefore, it is important to prevent decomposition by avoiding exposure to high temperatures.

3-18

Page 31 Page 33
Page 32
Image 32
Electrolux FKCH17F7HW Combustibility of HFC-134a, Leak Testing, Bulk Delivery and Storage, Filling and Charging Operations
Page 31 Page 33

FKCH17F7HW specifications

The Electrolux FKCH17F7HW is a standout refrigerator designed to meet the needs of modern households. With its sleek design and advanced features, it not only enhances the kitchen aesthetic but also promotes efficient food storage and preservation.

One of the key features of the FKCH17F7HW is its spacious interior. The refrigerator offers a generous capacity, making it ideal for families or individuals who like to stock up on groceries. Its flexible shelving system allows users to adjust the heights of shelves, accommodating very tall items and optimizing storage space.

The FKCH17F7HW comes equipped with advanced cooling technologies that ensure consistent temperature control. The Frost Free technology prevents the buildup of ice, saving users from the hassle of manual defrosting. This feature also allows for more efficient cooling, which in turn reduces energy consumption. The dynamic cooling system circulates air evenly throughout the refrigerator, helping to maintain an ideal temperature for perishable foods.

Another noteworthy characteristic is the humidity-controlled crisper drawers. These drawers provide an optimal environment for fruits and vegetables, keeping them fresher for longer. By regulating humidity levels, the crisper drawers also help to prevent spoilage, which not only saves money but contributes to less food waste.

In addition to storage practicality, the FKCH17F7HW incorporates energy-efficient technologies. The appliance is designed with an A+ energy rating, which means it operates with lower energy consumption without sacrificing performance. This eco-friendly feature not only benefits the environment but also reduces electricity bills.

The refrigerator also boasts user-friendly controls. Its intuitive electronic control panel makes it easy to adjust settings and ensure optimal performance. Moreover, the LED lighting illuminates the interior, making it easy to find what you need, even in low light conditions.

In summary, the Electrolux FKCH17F7HW is a remarkable refrigerator that combines style, functionality, and energy efficiency. With its generous capacity, advanced cooling technologies, and user-friendly features, it stands as a reliable appliance for any kitchen. Whether you're looking to preserve fresh produce or store family meals, this refrigerator meets a wide range of storage needs while maintaining an attractive design.
Top Page Image Contents