Epa 608 Technician Certification Study Guide

What are the typical uses of the center port of gauge set? - Answer- Used during evacuation, charging and recovery procedures. What color are the gauges on a manifold gauge set? - Answer- Low pressure is blue, High pressure is red. What are the typical ranges of pressure measurements used on the gauges of a manifold gauge set? - Answer- High side is 0 to 500 PSIG; Low side is 0 to 350 PSIG and 0 to 30 in. Hg below atmospheric pressure. Is the refrigerant leaving a condenser at a high or low pressure? Is it a liquid or a gas? - Answer- High pressure, liquid. Is the refrigerant entering the expansion valve (variable metering device) a liquid or gas? - Answer- Liquid, high pressure. Is the pressure of the refrigerant entering the compressor high or low? - Answer- Low pressure vapor. Where in a refrigerant circuit does a liquid boil to absorb heat? - Answer- In the evaporator. The refrigerant in the suction line is a gas that has been heated above its saturation. What is this condition called? - Answer- Superheated vapor. What can cause liquid refrigerant to migrate to a compressor crankcase? - Answer- If the compressor is located in the coldest location in the circuit. List two conditions that can quickly damage a compressor that is starting to run? - Answer- Operating while in a deep vacuum or when the service valves are closed. What system failures require taking an oil sample? - Answer- A compressor burnout or if the unit has had a leak. Is flushing with refrigerant an acceptable tube cleaning method? - Answer- No. In addition to preventing and repairing leaks what else should a technician do to conserve refrigerant? - Answer- Recover and recycle used refrigerants. What factors affect the speed of an evacuation? - Answer- Pump size, hose length, hose diameter, size of system to be evacuated, ambient temperature, suction line size, and the amount of moisture in the system.