User manual

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2. Evaporator Unit
• The WM-15SFC evaporator unit is installed for ceiling mount with the air
supply towards horizontally and air return on the bottom.
• The WM-19SFC evaporator unit is installed for wall mount with the air
supply towards top and air return on the sides.
• Supply and return air flow from the evaporator unit shall be unobstructed
for at least 1 foot.
• There is a gravity drain line so that it can not be installed above the
evaporator unit. Otherwise a condensation pump must be used.
3. Refrigeration Piping and Charging
NOTES: ALWAYS USE THE SUPERHEAT AND SUBCOOLING,
PRESSURE READINGS TO CHARGE REFRIGERANT PROPERLY, THE
LISTED CHARGES ARE FOR REFERENCE ONLY.
• The installation order starts from condensing unit (including the receiver),
liquid line filter-drier, moisture-liquid indicator (sight glass), liquid line,
evaporator unit (including liquid line solenoid valve and thermostatic
expansion valve or automatic expansion valve), returning to suction line
and condensing unit.
• The subcooling at the condensing unit shall be around 10°F. The charge
may be complete when there are no more bubbles forming in the sight
glass.
• The evaporator superheat is set around 8-10 °F for a 10 °F TD system at
factory.
• Low side pressure: around 33 psig
• High side pressure: 130 -150 psig at 75 -90 °F ambient temperatures
The line sizes and refrigerant charges are listed as follows.
MODEL
REFRIGERATION
LINES
LIQUID
LINE
SUCTION
LINE
DRAIN
LINE
CHARGE
VINO-1500SS < 50 FT
1/4"
OD
3/8” OD 1/2” OD
R134a/
15 OZ
VINO-1900SS < 50 FT
1/4"
OD
3/8” OD 3/8” OD
R134a/
15 OZ
4. Pressure, Superheat and Subcooling Readings
NOTES: THE SERVICE VALVES MUST BE IN THE MIDDLE POSITIONS TO
READ PROPERLY.
Complaint Possible Causes
a. High suction pressure and low head pressure
b. High suction pressure and low head pressure
Low superheat and low subcooling
a. Compressor may be bad
b. Expansion valve opened, too
much oil