1 Small Appliance Systems and Service Safety
Learn how small-appliance refrigeration circuits work, which Section 608 requirements apply to service and refrigerant recovery, and how to follow a safe service workflow.
What qualifies as a
A is factory-manufactured, factory-charged, hermetically sealed, and contains five pounds or less of refrigerant. A unit containing more than five pounds or one that is not factory-sealed may fall under different rules.
Examples include household refrigerators and freezers, room air conditioners, packaged terminal heat pumps, dehumidifiers, under-counter ice makers, vending machines, and drinking-water coolers.
How the refrigeration circuit works
A sealed refrigeration circuit moves heat from a cooler space to a warmer one. In a typical vapor-compression system, refrigerant passes through components that raise its pressure, release heat, lower its pressure, and absorb heat.
The raises the refrigerant vapor’s pressure and temperature.
The condenser releases heat as the refrigerant condenses into a liquid.
A capillary tube or another reduces refrigerant pressure.
The evaporator absorbs heat as the refrigerant boils back into vapor.
The helps remove moisture and contaminants from the circuit.
The precise design depends on the appliance. A refrigerator or freezer cools an insulated cabinet. A room air conditioner cools indoor air and rejects heat outdoors. A dehumidifier cools air to condense moisture, then reheats the air before returning it to the room. Ice makers, vending machines, and water coolers use refrigeration circuits to cool or freeze a product.
Certification and refrigerant
covers technicians who service small appliances. Connecting or disconnecting gauges or hoses, adding or removing refrigerant, and other work that can compromise a refrigerant circuit generally require the appropriate Section 608 certification. Apprentices may qualify for an exemption while closely and continually supervised by a certified technician.
Before opening a for service—or disposing of it—recover the refrigerant using equipment certified for small appliances. The federal requirement is met by one of these options:
With equipment made before November 15, 1993, recover of the refrigerant.
With equipment made on or after November 15, 1993, recover if the appliance works, or if it does not.
Alternatively, evacuate the appliance to four inches of mercury vacuum.
Follow the equipment manufacturer’s instructions. The four-inch-vacuum alternative is not a percentage- target. Do not intentionally vent refrigerant during service or disposal.
Safe service workflow
Use a deliberate, documented process for service.
Identify the appliance. Read its nameplate for refrigerant type, charge, electrical rating, and service information. Confirm that it meets the small-appliance definition.
Make the work area safe. Disconnect power before electrical work and verify that power is off. Use appropriate eye and hand protection, keep the area ventilated, check the refrigerant’s safety information, and use controls appropriate to its flammability. Eliminate ignition sources when required.
Inspect before connecting equipment. Look for damaged wiring, leaking joints, corrosion, blocked airflow, dirty coils, and a restricted or damaged condensate drain. Use tools and equipment compatible with the identified refrigerant.
Recover before opening the circuit. Use certified equipment and a suitable cylinder. Do not mix refrigerants. Keep cylinders upright, properly identified, and within their rated fill limits. Never heat a cylinder with an open flame.
Repair and verify. Use appropriate service procedures and materials. When brazing, protect nearby parts and follow safe practices, including using dry nitrogen for purging where specified—never oxygen or compressed air. Check for leaks before returning the appliance to service.
Document and clean up. Record the refrigerant handled and the work performed. Dispose of recovered refrigerant and other materials through appropriate channels.
If a refrigerator’s will not run, do not assume that the refrigerant circuit is empty. Diagnose the electrical or mechanical fault first. If the repair requires opening the sealed circuit, recover the charge to the applicable Type I requirement before opening it.