With system‐dependant recovery equipment, some special procedures may be necessary, depending on the condi‐
tion of the appliance. When using a system dependent recovery process on an appliance with an
operating com‐
pressor
, run the compressor and recover from the high side of the system. Usually, one access fitting on the high
side will be sufficient to reach the required recovery rate, as the appliance compressor should be capable of
pushing the refrigerant to the high side.
If the appliance has a
non‐operating compressor
, access to both the low and high side of the system may be
necessary. In order to achieve the required recovery efficiency, it will be necessary to take measures to help
release trapped refrigerant from the compressor oil, (heat and tap the compressor several times and/or use a
vacuum pump). Because appliances with non‐operating compressors cannot always achieve desired evacuation
rates utilizing system‐dependent recovery equipment, the EPA requires technicians to have at least one self‐
contained recovery device available at the shop to recover refrigerant from systems with non‐operating compres‐
sors. The exception to this rule is technicians working on small appliances only. System dependent devices may
only be used on appliances containing 15 lbs. of refrigerant or less.
Small appliances are equipped with a straight piece of tubing that can be used to install a piercing type access fit‐
ting. When installing an access fitting onto a sealed system, the fitting should be leak tested before proceeding
with recovery. It is generally recommended that solderless piercing type valves only be used on copper or alumi‐
num tubing material. These fittings tend to leak over time and should not be left on an appliance as a permanent
service fixture. After installing an access fitting, if you find that the system pressure is 0 psig., do not begin the
recovery process. If the appliance is equipped with a defrost heater, such as in a domestic frost‐free refrigerator,
operating the defrost heater will help to vaporize any trapped liquid refrigerant and will speed the recovery
process. If a strong odor is detected during the recovery process, a compressor burn‐out has likely occurred.
When recovering refrigerant from a system that experienced a compressor burn‐out, watch for signs of con‐
tamination in the oil. After recovering refrigerant, if nitrogen is used to flush debris out of the system, the nitro‐
gen may be legally vented.
Refrigerators built before 1950 may have used Methyl Formate, Methyl Chloride, or Sulfur Dioxide as refrigerant
and should not be recovered with current recovery devices. Small appliances used in campers or other recreational
vehicles may use refrigerants such as Ammonia, Hydrogen, or Water, and therefore should not be recovered us‐
ing current recovery equipment.
When filling a graduated charging cylinder with a regulated refrigerant, the refrigerant vapor that is vented off
the top of the cylinder must be recovered.
SAFETY & SHIPPING
The safety and shipping requirements for TYPE I certification are covered in the CORE section of this manual.
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