The control coil of AC Contactor no 24
V AC power
Check if the relay P2 of 3-minute timer board
have current output ,if not ,check if P1、 P3
have 24 V AC input ， if have 24V AC ，
please check if it keep for 3 minutes， if so
and P2 no output ，change the 3-minute
timer board； if keep time < 3 minutes ，P2
no output ; if P1 、P3 no24V AC， first
check the thermostat C 、Y terminal have
24 V AC，if no 24 V AC，then check the
thermostat or reset the setting temp.; if have
24 V AC ,check if the C Y and P1、 P3
connection wire cut off or fasten loosely，if
cut off ，then change the parts.
Run or start capacitor defective Replace
Loose connection Check and tighten all connections.
Compressor stuck, grounded or open
motor winding, open internal overload
Wait for 2 hours for overload to reset.
Replace compressor if still open.
Low voltage condition At compressor terminals, voltage must be
within 10% of rating plate volts when unit is
running.
Condenser fan runs,
compressor doesn’t
Low voltage condition Add start kit components
Replace
Loose connection Check and tighten all connections.
Fan stuck, grounded or open motor
winding, open internal overload
Wait for 2 hours for overload to reset.
Replace Fan if still open.
Low voltage condition At compressor terminals, voltage must be
within 10% of rating plate volts when unit is
running.
Defective overload protector Replace – check for correct voltage
Condenser fan
doesn’t
Refrigerant undercharge Add refrigerant
Register sweat Low evaporator airflow Increase blower speed or reduce restriction
– replace air filter
Restriction in liquid line, metering
device or filter drier
Replace defective components
Flowrator piston size too small Change to correct size piston
High head – Low
vapor pressures
Incorrect capillary tubes Change coil assembly
Blocked outdoor coil Clear away leaves and other debris
Refrigerant overcharge Correct system charge
Condenser fan not running Repair or replace
High head – High or
normal vapor
pressures
Air, non-condensibles or moisture in
system
Recover refrigerant, evacuate & recharge,
add filter drier
Flowcheck piston size too large Change to correct size piston
Defective compressor valves Replace compressor
Low head – High
vapor pressures
Incorrect capillary tubes Replace coil assembly
Low evaporator airflow Increase blower speed or reduce restriction
– replace air filter
Operating below 65 °F outdoors
Add low ambient kit
Low vapor – cool
compressor – iced
evaporator coil
Moisture in the system Recover refrigerant, evacuate & recharge,
add filter drier
Excessive load Recheck load calculation High vapor pressure
Defective compressor Replace
Fluctuating head and
vapor pressures
Air or non-condensibles in system Recover refrigerant, evacuate & recharge.
Pulsing noise at
metering device or
liquid line
Air or non-condensibles in system Recover refrigerant, evacuate & recharge
Compressor runs, Run capacitor defective
furnace trap
Condenser fan and
The outdoor power supply main circuit
AC Contact not connected to the
operation of condensate pump.
switch in “OFF” position or fuse
blown on main circuit
Reset the power supply switch to " ON"
position or change the fuse and confirm the
Contactor
main power lead to the
Re-connect the power supply wire, and
has voltage present.
compressor don’t run power supply wire or not tightly fasten t ightly fasten.
31
Central Air Conditioning Model: Condensing Unit, HC13-D2
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