Troubleshooting
www.DaikinApplied.com 89
IM 971-3 • MAVERICK I
Troubleshooting
Cooling Troubleshooting Chart
DANGER
Disconnect all power to unit before servicing. Contactor may break only one side. Failure 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
• Thermostat out of calibration-set too high
• Failed contactor
• Blown fuses
• Transformer defective
• High pressure control open (if provided)
• Interconnecting low voltage wiring damaged
• Check for correct voltage at compressor contactor in control box
• Reset
• Check for 24 volts at contactor coil replace if contacts are open
• Replace fuses
• Check wiring-replace transformer
• Reset-also see high head pressure remedy – The high pressure control
opens at 450 PSIG
• Replace thermostat wiring
Condenser fan runs,
compressor doesn’t
• Loose connection
• Compressor stuck, grounded or open motor
winding, open internal overload.
• Low voltage condition
• Check for correct voltage at compressor check & tighten all connections
• Wait at least 2 hours for overload to reset. If still open, replace the
compressor.
• At compressor terminals, voltage must be within 10% of rating plate volts
when unit is operating
• Add start kit components
Insufficient cooling
• Improperly sized unit
•
Improper airflow
• Incorrect refrigerant charge
• Air, non-condensable or moisture in system
• Incorrect voltage
• Recalculate load
• Check should be approximately 400 CFM per ton.
• Charge per procedure attached to unit service panel
•
Recover refrigerant, evacuate & recharge, add filter drier
• At compressor terminals, voltage must be within 10% of rating plate volts
when unit is operating.
Compressor short cycles
• Incorrect voltage
• Defective overload protector
• Refrigerant undercharge
• At compressor terminals, voltage must be ±10% of nameplate marking
when unit is operating.
• Replace check for correct voltage
• Add refrigerant
Registers sweat
•
Low evaporator airflow
•
Increase speed of blower or reduce restriction replace air filter
High head-low vapor pressures
•
Restriction in liquid line, expansion device or filter
drier
• Flow check piston size too small
• Incorrect capillary tubes
• Remove or replace defective component
• Change to correct size piston
• Change coil assembly
High head-high or normal vapor
pressure Cooling mode
• Dirty condenser coil
• Refrigerant overcharge
• Condenser fan not running
• Air or non-condensable in system
• Clean coil
• Correct system charge
• Repair or replace
• Recover refrigerant, evacuate & recharge
Low vapor – cool compressor
iced evaporator coil
• Defective Compressor valves
• Incorrect capillary tubes
• Replace compressor
• Replace coil assembly
Low vapor cool evaporator coil
•
Low evaporator airflow
• Operating below 65°F outdoors
• Moisture in system
•
Increase speed of blower or reduce restriction replace air filter
• Add Low Ambient Kit
•
Recover refrigerant evacuate & recharge add filter drier
High vapor pressure
• Excessive load
• Defective compressor
• Recheck load calculation
• Replace
Fluctuating head & vapor
• Air or non-condensate in system
• Recover refrigerant, evacuate & recharge
Gurgle or pulsing noise at
expansion device or liquid line
• Air or non-condensable in system
• Recover refrigerant, evacuate & recharge
Summary of Contents for Maverick I MPSA07D
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