EPA 608 Type 3 Knowledge Requirements

HVAC Manifold Gauges

Summary of Knowledge Required for the Low-Pressure Examination

Know the preferred order of pressurization methods for leak-testing low-pressure refrigeration systems.
1. Hot-water method. (Or built-in system heating equipment)
2. Nitrogen testing method.
Know the signs of leakage into a low-pressure system. For example excess purging.
Know the maximum pressure for leak-testing low-pressure centrifugal chillers.
Know the leak-inspection requirements for appliances that are exceeding the accepted leak rate.
Know the reporting requirements for chronically leaking appliances.

Know the allowable annual leak rate for commercial and industrial refrigeration.
Know the allowable annual leak rate for other appliances with over 50lbs of refrigerant.

Know that recovering liquid refrigerant at the beginning of the recovery process helps speeds up recovery.
Know that you need to recover the refrigerant vapor as well as the liquid refrigerant.
Know that before removing the system oil it needs to be heated to 130 F to minimize refrigerant release.
Know that you need to circulate or remove the water from a chiller during refrigerant evacuation in order to prevent freezing.
Know the high-pressure safety cutout level of recovery devices used for low-pressure appliances.

Know that you need to introduce refrigerant vapor before refrigerant liquid to prevent freezing of water in the tubes.
Know that you need to charge centrifugal systems through the evaporator charging valve.

Know the refrigerant evacuation requirements for low-pressure appliances in each of the following situations:
- Evacuation requirements for disposal of appliances and components.
- Evacuation requirements for major repairs and what defines a major repair.
- Evacuation of leaky versus non-leaky appliances.
- Evacuation requirements for appliances or components containing less than 200 pounds of refrigerant versus those containing more than 200 pounds of refrigerant.
- Evacuation requirements using recovery and recycling equipment built before November 15th 1993 versus using equipment built after November 15th 1993.
Know the definition what major and non-major repairs are in terms of evacuation/recovery requirements.
Know the allowable methods for pressurizing a low-pressure system for a non-major repair (controlled hot water and system heating/pressurization)
Knowledge of the need to wait a few minutes after reaching the required recovery vacuum to see if system pressure continues to rise, indicating there is still liquid refrigerant in the system or in the oil.

Know the equipment room requirements mandated by ASHRAE Standard 15 requires an oxygen deprivation sensor with all refrigerants.
Knowledge that under the ASHRAE Standard 15, equipment rooms also are required to have a refrigerant sensor for R-123.