Daikin MPS015B User Manual

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Troubleshooting Charts
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.
Table 18: Cooling Troubleshooting Chart
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 450 PSIG
Interconnecting low voltage wiring damaged Replace thermostat wiring
Condenser fan runs,
compressor doesn’t
Loose connection Check for correct voltage at compressor check & tighten all connections
Compressor stuck, grounded or open motor winding,
open internal overload.
Wait at least 2 hours for overload to reset. 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 Add start kit components
Insu󰀩cient cooling
Improperly sized unit Recalculate load
Improper airow Check should be approximately 400 CFM per ton.
Incorrect refrigerant charge Charge per procedure attached to unit service panel
Air, non-condensable or moisture in system Recover refrigerant, evacuate & recharge, add lter 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 airow Increase speed of blower or reduce restriction replace air lter
High head-low vapor
pressures
Restriction in liquid line, expansion device or lter
drier
Remove or replace defective component
Flow check piston size too small Change to correct size piston
Incorrect capillary tubes Change coil assembly
High head-high or normal
vapor pressure Cooling mode
Dirty condenser coil Clean coil
Refrigerant overcharge Correct system charge
Condenser fan not running Repair or replace
Air or non-condensable in system Recover refrigerant, evacuate & recharge
Low vapor - cool compressor
iced evaporator coil
Defective compressor valves Replace compressor
Incorrect capillary tubes Replace coil assembly
Low vapor cool evaporator
coil
Low evaporator airow Increase speed of blower or reduce restriction replace air lter
Operating below 65°F outdoors Add Low Ambient Kit
Moisture in system Recover refrigerant evacuate & recharge add lter drier
High vapor pressure
Excessive load Recheck load calculation
Defective compressor 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

Daikin MPS015B Specifications

General

Brand	Daikin
Model	MPS015B
Category	Heat Pump
Language	English