1- Determine the performance of the equipment with the existing refrigerant.
• Use the System Information Sheet provided below.
• Note the type of oil used and the operating data of the system (if the system is operating properly). • Check for leaks and repair.
2. Remove the refrigerant charge in the system. (A 10 to 15 inch Hg vacuum [50 to 67 kPa] is required to remove the load.)
• Use a recovery cylinder (DO NOT drain into the atmosphere).
• Weigh the amount of refrigerant removed (if possible):
• Eliminate the vacuum with dry nitrogen.
3. Replace the dryer filter.
• Check the elastomer seals (filter rings, sight glasses, etc.).
• Check that the oil is in good condition. Replace if necessary.
4. Evacuate the system and check for leaks.
• Does the system maintain a vacuum?
• Eliminate the vacuum with dry nitrogen, pressurize to a pressure below the design pressure of the system.
• Does the system maintain pressure?
• Check for any leaks.
5. Charge the system with refrigerant
• Remove the charge from the refrigerant only in the liquid phase of the cylinder.
• The initial charge should be approximately 85% of the standard R-22 charge. The final load will be approximately 95%
6. Adjust the refrigerant charge to obtain the same superheat as the original system. If the adjustment is not adequate, replace the TXV hole. (TXV: expansion valve)
7. Monitor the compressor oil levels. If necessary, add additional oil to reach the normal Operation level (middle of the display).
• If there is a sudden variation in the oil level (eg during or shortly after thawing), remove a small amount (approximately 10%) of the mineral oil and replace with POE. Repeat if necessary.
• If the oil level falls below the minimum, top up the oil to the minimum level with the type of oil available.
• If the oil level drops continuously or if large fluctuations occur during operation, add a sufficient amount of equivalent POE until the return oil is normal.
8. Clearly identify the system. Ensure that the System Information Sheet is completed and filed in a safe place.
Retrofit is complete!
