20
ES SPLIT INSTALLATION MANUAL
Checking Superheat and Subcooling
Determining Superheat
Measure the temperature of the suction line at the point where the expansion valve bulb is clamped.
Determine the suction pressure in the suction line by attaching refrigeration gauges to the schrader connection on
the suction side of the compressor.
Convert the pressure obtained in Step 2 to the saturation temperature by using the R-410A Pressure/Temperature
Conversion Chart on page 26.
Subtract the temperature obtained in Step 3 from Step 1. The difference is the amount of superheat for the unit. Refer
to tables on pages 21-22 for superheat ranges at specifi c entering water conditions. The fi gure below illustrates a
typical example of how to measure superheat on the unit using R-410A. The temperature of the suction line at the
sensing bulb is 50°F. The suction pressure at the compressor is 114 PSIG which is equivalent to 38°F saturation
temperature (R-410A Pressure/Temeprature Conversion Chart, page 26).
50°F - 38°F = 12°F Superheat
Determining Subcooling
Measure the temperature of the liquid line on the small refrigerant line (liquid line) just outside the split cabinet. This
location will be adequate for measurement in both modes unless a signifi cant temperature drop in the liquid line is
anticipated.
Measure the liquid line pressure by attaching refrigerant gauges to the schrader connection on the liquid line service
valve.
Convert the pressure obtained in Step 2 to the saturation temperature by using the R-410A Pressure/Temperature
Conversion Chart on page 26.
Subtract the temperature in Step 1 from the temperature in Step 3. The difference will be the subcooling value for
that unit. Refer to tables on pages 21-22 for values at specifi c entering water temperatures. The fi gures below
illustrate a typical example of measuring refrigeration subcooling using R-410A. The temperature of the liquid line
after leaving the condensing coil is 90°. The liquid line pressure at the service valve is 356 PSIG, which is equivalent
to 108°F.
108°F - 90°F = 18°F Subcooling
1.
2.
3.
4.
1.
2.
3.
4.
Expansion
Valve Bulb
114 psig = 38°F
Suction Line =
50
o
F
114 psig (see chart) =
-38
o
F
Superheating =
12
o
F
Temperature
at Suction of
Compressor
= 50°F
Figure 11: Subcooling Check
Temperature of Liquid Line
Outside the ES Cabinet.
Use in Both Modes.
356 psig
= 108°F
Suction Line
Temperature of Liquid
Line = 90°F
Liquid Line
356 psig (see chart) = 108
o
F
Liquid Line =
-90
o
F
Subcooling =
18
o
F
Figure 12: Superheat Check