| Questions |
Cause |
Remedy |
| Have you checked oil charge? |
Insufficient compressor oil |
Add oil to proper level |
| Have you checked refrigerant charge? |
Shortage of refrigerant |
Repair leak and recharge |
| Have you checked pressure drop across coil? |
Evaporator design |
Change coil to get higher gas velocity |
| Was proper oil gas ratio met at start-up? |
Gas-oil ratio low |
Add 1pint oil for each 10 pounds of refrigerant added to factory charge |
| Have you checked expansion valve? |
Plugged expansion valve or strainer |
Clean or replace |
| Do you have traps near evaporator and in vertical risers as necessary? |
Oil trapping in lines |
Add traps as needed. Drain tubing toward compressor |
| Does unit short cycle? |
Short cycling |
Refer to section II |
| Have you checked your evaporator superheat? |
Refrigerant flood back |
Change location of expansion valve bulb or adjust valve to return wet gas to compressor |
