Unit 10: System Charging
Objectives
- After studying this unit, you should be able to
- describe how refrigerant is charged into systems in the vapor and liquid states.
- state the advantage of using electronic scales for weighing refrigerant into a system.
- describe the terms “temperature glide” and “fractionation” as they apply to blended refrigerants.
- charge air-conditioning systems with fixed orifice, capillary tube, or piston-type metering devices using charging charts and curves.
- use the subcooling method of charging to charge air-conditioning and heat pump systems that incorporate a thermostatic expansion valve (TXV) as the metering device.
- use temperature/pressure charts to help properly charge air-conditioning and refrigeration systems.
- differentiate between “bubble point” and “dew point” values on a temperature/pressure chart and properly use these values to calculate superheat and subcooling values on systems that operate with blended refrigerants.
Next: Advance to the Learning Center Dashboard and complete the lessons.