Type II Certification
Required for technicians handling medium, high, and very high-pressure appliances (excluding small appliances and MVAC systems).
Applies to commercial refrigeration, comfort cooling, and industrial process refrigeration.
System Classifications
Comfort Cooling: Used to control temperature and humidity in occupied spaces (e.g., residential, office buildings).
Commercial Refrigeration: Preserves products, used in sectors like retail food and cold storage.
Industrial Process Refrigeration (IPR): If an appliance has dual uses, the higher percentage of use determines its classification.
Determining System Charge
Use the equipment nameplate for packaged systems to determine the refrigerant charge.
Split-systems require calculated charge values (factory charge + piping and accessory charges).
Example: A system with an 80 lb nameplate charge requires liquid charging through the liquid-line service valve.
Type II Leak Repair Requirements
Leak Thresholds (as of 2019):
Comfort Cooling: 10% annual leak rate.
Commercial Refrigeration: 20% annual leak rate.
Industrial Process Refrigeration: 30% annual leak rate.
Repair Requirements: Appliances with a charge ≥50 lbs and exceeding the threshold must be repaired, retrofitted, or retired.
Leak Repair Time Frames
30 Days: Owners/operators have 30 days to complete repairs once a leak threshold is exceeded.
Follow-up: A verification test is required within 10 days if ≥200 lbs of refrigerant is added.
Section 608 Leak Repair Regulations
Leak Inspections: Required for appliances exceeding the maximum allowable leak rate.
Inspection Frequency:
Over 500 lbs: Inspect every three months.
50–500 lbs: Inspect annually.
Record Keeping
Maintain records of leak inspections, verifications, and repairs for three years.
The equipment owner/operator is responsible for these records.
Leak Detection Methods
Dry Nitrogen with Tracer Gas: Pressurize the system with dry nitrogen and a small amount of refrigerant for leak detection.
Indicators: Oil traces on rotating shafts indicate possible leaks.
Recovery Techniques
Preparation: Determine maximum system charge; systems >15 lbs require active recovery methods.
Enhancing Recovery: Connect service hoses to the liquid line and use recovery in liquid phase when possible to speed up the process.
Cylinder Handling: Reduce pressure in an empty cylinder before transferring refrigerant.
Evacuation Levels During Recovery
Evacuation Levels (required for appliances with different pressure levels):
Very High Pressure: 0 inches Hg.
High Pressure (<200 lbs): 0 inches Hg.
High Pressure (≥200 lbs): 10 inches Hg.
Medium Pressure (<200 lbs): 10 inches Hg.
Medium Pressure (≥200 lbs): 15 inches Hg.
Refrigeration System Accessories
Liquid-Line Sight Glass: Used to check for moisture; located before the filter drier.
Accumulator: Found on the suction line, preventing liquid refrigerant from entering the compressor.
System Evacuation
Target: Evacuate to 500 microns to ensure all moisture and non-condensables are removed.
Evacuation Factors: Ambient temperature, system size, and vacuum line dimensions affect evacuation speed.
Pressure-Temperature Chart
Use in Charging: Reference P-T charts to match refrigerant pressures with temperatures and verify no non-condensables are present.
Safety Protocols
Personal Protection: Use safety glasses, gloves, and nitrogen regulator.
Evacuation and Recovery Precautions: Avoid energizing hermetic compressor motors in deep vacuum and follow manufacturer’s guidelines to prevent overheat or compressor damage.
Handling High-Pressure Systems: Monitor closely for temperature changes to prevent accidents or component failure.
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