TYPE II CERTIFICATION
Technicians maintaining, servicing, repairing or disposing of high pressure or very high‐pressure appliances, except
small appliances and motor vehicle air conditioning systems (MVAC), must be certified as a Type II Technician or a
Universal Technician.
LEAK DETECTION
After the installation of any type of system, the unit should first be pressurized with nitrogen (an inert gas) and leak
checked. In order to determine the general area of a leak use an electronic or ultrasonic leak detector. Once the gen‐
eral area of the leak is located the use of soap bubbles will pinpoint the leak.
A refrigeration unit using an open compressor that has not been used in several months is likely to leak from the rotat‐
ing shaft seal. During a visual inspection of any type of system, traces of oil are an indicator of a refrigerant leak. Exces‐
sive superheat, caused by a low refrigerant charge, is also an indication of a leak in a high‐pressure system.
LEAK REPAIR REQUIREMENTS
EPA regulations require that all
comfort cooling appliances containing more than 50 lbs
. of refrigerant MUST be re‐
paired when the annual leak rate exceeds
15%.
EPA regulations require that
all Commercial and Industrial Process Refrigeration
containing more than 50 lbs.
of re‐
frigerant MUST be repaired when the annual leak rate exceeds
35%.
RECOVERY TECHNIQUES
Proper recovery techniques begin with the use of appropriate recovery equipment that has been certified by an EPA
approved laboratory (UL or ETL) to meet or exceed ARI standards.
Recovered refrigerants may contain acids, moisture, and oil. It is therefore necessary to frequently check and change
both the oil and filter on a recycling machine. Both recycling and recovery equipment using hermetic compressors
have the potential to overheat when drawing a deep vacuum because the unit relies on the flow of refrigerant through
the compressor for cooling. Before using a recovery unit you should always check the service valve positions, the oil
level of the recovery unit, and evacuate and recover any remaining refrigerant from the unit’s receiver.
Technicians working with multiple refrigerants, before recovering and/or recycling a different refrigerant, must purge
the recover/recycle equipment by recovering as much of the first refrigerant as possible, change the filter, and evacu‐
ate. The only exception to this rule is for technicians working with R‐134a who must provide a special set of hoses,
gauges, vacuum pump, recovery or recovery/recycling machine, and oil containers to be used with R‐134a only.
Although recovering refrigerant in the vapor phase will minimize the loss of oil, recovering as much as possible in the
liquid phase can reduce recovery time. The technician may choose to speed up the recovery process by packing the re‐
covery cylinder in ice and/or applying heat to the appliance. After recovering liquid refrigerant, any remaining vapor is
condensed by the recovery system.
When performing refrigerant system service on a unit that has a receiver/storage tank, refrigerant should be placed in
the receiver. Refrigerant should be removed from the condenser outlet if the condenser is below the receiver. In a
building that has an air‐cooled condenser on the roof and an evaporator on the first floor, recovery should begin from
the liquid line entering the evaporator.
After recovery, refrigerant may be returned to the appliance from which it was removed or to another appliance
owned by the same person without being recycled or reclaimed, unless the appliance is an MVAC (Motor Vehicle Air
Conditioner) like appliance. The technician should always evacuate an empty recovery cylinder before transferring
refrigerant to the cylinder. Quick couplers, self‐sealing hoses, or hand valves should be used (as low loss fittings) to
minimize refrigerant release when hoses are connected and disconnected.
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