Carrier PTV Installation, Start-Up And Service Instructions Manual page 54

Table 32 -- WSHP Troubleshooting (cont)
FAULT HEATING
High Head Pressure X
Low Suction Pressure
Low Discharge Air
Temperature in Heating
High Humidity
Low Refrigerant Suction
Pressure
High Refrigerant Superheat
High Refrigerant
Subcooling
x
x
x
x
COOLING
X
X
x
x
x
x
x
x
x
x
x
x
x
x
x
POSSIBLE CAUSE
Reduced or no airflow in heating
Reduced or no water flow in
cooling
Inlet water too hot
Air temperature out of range in
heating
Scaling in water heat exchanger
Unit overcharged
Noncondensables in system
Restricted metering device
Reduced water flow in heating
Water temperature out of range
Reduced airflow in cooling
Air temperature out of range
Insufficient charge
Too high airflow
Poor performance
Too high airflow
Unit oversized
X Normal operation
X Reduced water flow
X Water temperature out of range
X Scaling in water to refrigerant
heat exchanger
X Reduced airflow
Return air temperature below
minimum
SOLUTION
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
External static too high. Check blower performance per Tables 9-13.
Check pump operation or valve operation/setting.
Check water flow adjust to proper flow rate. See Tables 19 and 24.
Check load, loop sizing, loop backfill, ground moisture.
Bring return-air temperature within design parameters.
Perform condenser cleaning.
Check superheat and subcooling. Reweigh in charge.
Remove refrigerant, evacuate system and charge unit.
Check superheat and subcooling per Tables 20-23. Replace.
Check pump operation or water valve operation/setting.
Plugged strainer or filter. Clean or replace.
Check water flow adjust to proper flow rate.
Bring water temperature within design parameters.
Check for dirty air filter and clean or replace.
Check fan motor operation and airflow restrictions.
External static too high. Check blower performance per Tables 9-13.
Too much cold vent air. Bring entering air temperature within design
parameters.
Check for refrigerant leaks.
Check blower performance per Tables 9-13.
See "Insufficient Capacity."
Check blower performance per Tables 9-13
Recheck loads and sizing check sensible cooling load and heat pump
capacity.
Check/compare with unit Installation Manual for typical operating temper-
atures and pressures chart.
Check pump operation.
Check strainer or filter.
Improper flow regulator.
Bring water temperature within proper range.
Conduct water quality analysis.
Check for dirty air filter.
Check for dirty air coil.
Check fan motor operation.
External static pressure exceeds fan operating parameters.
Space temperature too cold.
Excessive fresh air.
Check for leaking ductwork.
X Locate and repair leak.
X Locate bulb on suction line between reversing valve and compressor.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Supply air bypassing to return air
stream (zone systems).
Insufficient refrigerant charge
Improperly located TXV sensing
bulb
Failed or restricted metering
device
Insufficient refrigerant charge
Improperly located TXV sensing
bulb
Failed or restricted metering
device
Excessive refrigerant charge
Failed or restricted metering
device
Normal operation
Insufficient refrigerant charge
Failed or restricted metering
device
Failed or restricted metering
device
X
X
TXV and/or Low Pressure X
Tubing Frosting X
X
Equalizer Line Condensing
or Frosting
Failed TXV power head, capillary or sensing bulb.
Plugged TXV strainer.
Locate and repair leak.
Locate bulb on suction line between reversing valve and compressor.
Failed TXV power head, capillary or sensing bulb.
Plugged TXV strainer.
Remove refrigerant as needed.
Failed TXV power head, capillary or sensing bulb.
Plugged TXV strainer.
May occur when entering water temperature is close to minimum.
Locate and repair leak.
Failed TXV power head, capillary or sensing bulb.
Plugged TXV strainer.
Failed TXV power head, capillary or sensing bulb.
Plugged TXV strainer.
LEGEND
LED -- Light-Emitting Diode
RV -- Reversing Valve
TXV -- Thermostatic Expansion Valve
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