Fillable Printable 404A Pressure Temperature Sample Chart

404A Pressure Temperature Sample Chart

°FR‐404A

‐500.6

‐452.7

‐405

‐357.6

‐3010.4

‐2513.4

‐2016.8

‐1520.5

‐1024.5

‐528.8

033.5

538.6

1044

1549.9

2056.2

2563

3070.3

3578.1

4086.4 SYSTEM PROBLEM DISCH PRESS SUCT PRESS SUPERHEAT SUBCOOLING AMP DRAW

4595.2 OVERCHARGEHIGH\\HIGHHIGH

50104.7 UNDERCHARGE\LOWHIGH\\

55114.7 LIQUID RESTRICT.\LOWHIGH\LOW

60125.3 LOW EVAP FLOW\LOWLOW\\

65136.6 DIRTY CONDENSERHIGH\\\HIGH

70148.6 LOW AMBIENT °FLOW LOWHIGHHIGH\

75161.2 TXV BULB BAD\LOWHIGH\\

80174.6

85188.8

90203.7

95219.4

100235.9

105253.4

110271.7

115290.9

120311.1

125332.3

130354.5

135377.8

140402.2

145427.7

150454.4

Subcooling is determined by taking the high side pressure gauge reading, converting that

pressure to temperature using a PT chart, and then subtracting that temperature from

the actual temperature measured (using an accurate thermometer or thermocouple) at

the same point the pressure was taken.

404A PRESSURE‐TEMPERATURE CHART

REFRIGERATION SYSTEM ANALYSIS

WHAT IS SUPERHEAT & SUBCOOLING AND HOW TO MEASURE IT

Superheat refers to the number of degrees a vapor is above its saturation temperature

(boiling point) at a particular pressure.

Superheat is determined by taking the low side pressure gauge reading, converting that

pressure to temperature using a PT chart, and then subtracting that temperature from

the actual temperature measured (using an accurate thermometer or thermocouple) at

the same point the pressure was taken.

Subcooling is the condition where the liquid refrigerant is colder than the minimum

temperature (saturation temperature) required to keep it from boiling and, hence,

change from the liquid to a gas phase.