Rheem H2AC, Руководство по установке

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43
WARNING
!
FIGURE 20
COOLING TROUBLE SHOOTING CHART
DISCONNECT ALL POWER TO UNIT BEFORE SERVICING. CONTACTOR MAY BREAK ONLY ONE SIDE. FAIL-
URE TO SHUT OFF POWER CAN CAUSE ELECTRICAL SHOCK RESULTING IN PERSONAL INJURY OR DEATH.
SYMPTOM POSSIBLE CAUSE REMEDY
Unit will not run • Power off or loose electrical connection • Check for correct voltage at compressor contactor in control
box
• Thermostat out of calibration-set too high • Reset
• Failed contactor • Check for 24 volts at contactor coil - replace if contacts are
open
• Blown fuses • Replace fuses
• Transformer defective • Check wiring-replace transformer
• High pressure control open (if provided) • Reset-also see high head pressure remedy-The high pressure
control opens at 610 PSIG
• Interconnecting low voltage wiring damaged • Replace thermostat wiring
Condenser fan runs, compressor • Loose connection • Check for correct voltage at compressor -
doesn’t check & tighten all connections
• Compressor stuck, grounded or open motor winding • Wait at least 2 hours for overload to reset.
open internal overload. If still open, replace the compressor.
• Low voltage condition • At compressor terminals, voltage must be within 10% of rating
plate volts when unit is operating.
• Low voltage condition • Increase voltage
Insufficient cooling • Improperly sized unit • Recalculate load
• Improper airflow • Check - should be approximately 400 CFM per ton.
• Incorrect refrigerant charge • Charge per procedure attached to unit service panel.
• Air, non-condensibles or moisture in system • Recover refrigerant, evacuate & recharge, add filter drier
• Incorrect voltage • At compressor terminals, voltage must be within 10% of rating
plate volts when unit is operating.
Compressor short cycles • Incorrect voltage • At compressor terminals, voltage must be ± 10% of
nameplate marking when unit is operating.
• Defective overload protector • Replace - check for correct voltage
• Refrigerant undercharge • Add refrigerant
Registers sweat • Low evaporator airflow • Increase speed of blower or reduce restriction - replace air
filter
High head pressure- • Restriction in liquid line, expansion device or filter drier • Remove or replace defective component
low vapor pressures • TXV does not open • Replace TXV
High head pressure-high or • Dirty condenser coil • Clean coil
normal vapor pressure - • Refrigerant overcharge • Correct system charge
Cooling mode • Condenser fan not running • Repair or replace
• Air or non-condensibles in system • Recover refrigerant, evacuate & recharge
Low head pressure-high vapor • Defective Compressor valves • Replace compressor
pressures
Low vapor pressure - • Low evaporator airflow • Increase speed of blower or reduce restriction - replace air
cool compressor - filter
iced evaporator coil • Operating below 65°F outdoors • Add Low Ambient Kit
• Moisture in system • Recover refrigerant - evacuate & recharge - add filter drier
High vapor pressure • Excessive load • Recheck load calculation
• Defective compressor • Replace
Fluctuating head & vapor • TXV hunting • Check TXV bulb clamp - check air distribution on coil - replace
pressures TXV
• Air or non-condensibles in system • Recover refrigerant, evacuate & recharge
Gurgle or pulsing noise at • Air or non-condensibles in system • Recover refrigerant, evacuate & recharge
expansion device or liquid line
XII. TROUBLESHOOTING