Type II — High-Pressure第 131 / 240 题
A technician checks the charge on an R-22 system that uses a fixed orifice (piston) metering device. Which measurement is the primary method to verify the charge?
a.Subcooling at the condenser outlet
b.Compressor amperage only
c.Superheat at the evaporator or compressor inlet
d.Discharge line temperature only
解析
On a fixed-orifice system, superheat is the primary way to check the charge; the technician compares measured superheat to a target from the manufacturer's chart. Subcooling is the preferred method on TXV systems, not fixed-orifice systems. Superheat is the difference between the actual suction temperature and the saturation temperature at the suction pressure.
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