System Evacuation and Charging Procedures Flashcards
6 cards from real EPA 608 609 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 System Evacuation and Charging Procedures flashcards as text
How must a blended (zeotropic) refrigerant be added to a system during charging?
Answer: As liquid only
Zeotropic blends like R-410A and R-404A must be charged as liquid to prevent fractionation, which would alter the blend's composition and performance.
What does the blue (low-side) gauge on a manifold gauge set measure?
Answer: Low-side suction pressure
The blue gauge measures low-side (suction) pressure, which corresponds to the evaporator pressure and is used to assess evaporator conditions.
When charging a single-component refrigerant into an operating system, in what state should it enter the suction line?
Answer: Vapor (gas) only
Single-component refrigerants like R-22 can be safely charged as vapor into the suction line of a running system without risk of slugging the compressor.
What does measuring superheat help a technician determine when charging a system with a fixed-orifice metering device?
Answer: Proper refrigerant charge level
In fixed-orifice systems, suction line superheat directly reflects the refrigerant charge level — too high indicates undercharge, too low indicates overcharge.
When using the subcooling method to verify charge in a TXV system, where is the liquid line temperature measured?
Answer: At the liquid line near the condenser outlet
Subcooling is measured at the liquid line leaving the condenser, comparing actual temperature against saturation temperature at the measured high-side pressure.
What manifold gauge readings typically indicate an overcharged refrigeration system?
Answer: Both suction and discharge pressures above normal
Overcharging floods the evaporator with excess liquid refrigerant, raising suction pressure, while the condenser must reject extra heat, raising discharge pressure.