Type II — High-PressureCâu 152 / 240
A technician measures subcooling of 3°F on a TXV-equipped R-410A system when the manufacturer specifies 10°F of subcooling. What does the low subcooling most likely indicate?
a.The system is overcharged
b.The system is likely undercharged (low on refrigerant)
c.The TXV is oversized
d.There is too much liquid in the condenser
Giải thích
On a TXV system, subcooling lower than the manufacturer's target usually means the system is undercharged, because there is not enough liquid backing up in the condenser to be subcooled. The technician would add refrigerant slowly and recheck subcooling. High subcooling, by contrast, generally indicates an overcharge.
Luyện miễn phí toàn bộ 240 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A technician is about to add liquid refrigerant into the suction line of a running compressor to charge faster. Why is this dangerous on a Type II system?
- A technician replaces a leaking evaporator on an R-410A system and must protect the new POE oil during the repair. Why is POE oil handling important?
- Virgin (newly produced) HCFC-22 was subject to a production and import phaseout. As of January 1, 2020, what happened to the supply of virgin R-22?
- Before opening a Type II system for a compressor change, a technician recovers the refrigerant. Which sequence best protects both the technician and the environment?
- A technician performs a standing pressure (leak) test on a repaired Type II system using dry nitrogen. Over several hours the pressure holds steady with no drop. What does this indicate?
- A technician is selecting a vacuum pump to properly dehydrate a Type II R-410A system. Why is a dedicated vacuum pump used instead of the recovery machine to pull the final vacuum?
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