Structural Concepts FSI656R User Manual page 35

TROUBLESHOOTING - EVAPORATOR SYSTEM (BY TRAINED SERVICE PROVIDERS ONLY)
CONDITION
Low Suction Pressure
High Suction Pressure
Check if sight glass is flashing or showing low charge.
Check that expansion valve (TXV) isn't restricted. Check element charge.
Check that liquid line or filter isn't restricted. Check that refrigeration lines
and/or hoses are not kinked on either high or low sides.
Check that evaporator fan motors are working.
Check that superheat is between 6 °F to 8 °F.
Check that there is no air recirculation around evaporator coil.
Check that evaporator coil is not iced up.
Check for refrigerant overcharge.
Check that compressor reed valves aren't bad. Look for high suction/low
head pressure. Perform pump down.
Check that the "cooling load" isn't high. Product must be pre-chilled before
placing in refrigerated section of case.
Check that case is at least 15-feet from exterior doors, overhead HVAC
vents or any air curtain disruption.
Check that unit is not exposed to direct sunlight via windows or any other
heat source (ovens, fryers, etc.).
Check that superheat adjustment isn't low.
Check TXV bulb installation
a. Poor thermal contact.
b. Warm location.
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TROUBLESHOOTING