Commercial Air Conditioner
Model: heat pump, 10SEER UNITS
41
.Break each vacuum with dry nitrogen to 3.0 psi.
Use the largest connections and hoses possible to expedite the process.
J. Charge with clean ,new or reclaimed R-22 refrigerant .Charge in accordance with proper
charging procedures.
K. Check ,and change as needed ,after 24 hours of run time to verify the unit is free of acid.
7. Other Check Points
A. Verify the operating voltage is within the specified range.
B. Check that all wiring connections are tight and proper.
C. Verify that all fuses or circuit breakers are of the proper type.
D. Ensure the air conditioning operates properly in cooling.
E. Inspect all the other electrical components for proper operation.
F. Ensure the thermostat and subbase are correct and operate properly.
G. Ensure all ducts and air moving device are sized and operate properly.
H. Ensure the refrigerant piping is sized correctly and not pinched.
I. Ensure all the system are in correct position.
10.3Troubleshooting Guide
! WARNING
– Disconnect all electrical power to the unit before servicing. Disconnect power to both the indoor
and outdoor units. NOTE: There may be more than one electrical disconnect switch. Failure to shut off power can
cause electrical shock resulting in personal injury or death.
Symptom Possible
Cause
Remedy
Power off or loose electrical
connection
Make sure main switch is ON. Check and
tighten all connections.
No cooling
Incorrect thermostat setting
Set thermostat correctly
Dirty filters
Clean & replace
Indoor air blockage
Check supply registers and return grills for
blockage.
Blocked outdoor coil
Clear away leaves and other debris
Improperly sized unit
Recalculate load
Improper airflow
Check – should be 400CFM/Ton
Incorrect refrigerant charge
Charge correctly per instruction.
Air, non-condensable or moisture in
system
Recover refrigerant, evacuate & recharge,
add filter drier
Insufficient Cooling
Incorrect voltage
At compressor terminals, voltage must be
within 10% of rating plate volts when unit is
running.
Water on floor or in
furnace
Blocked condensate drain and “P”
trap
Remove blockage
AC Contact not connect to the power
supply wire or not tightly fasten.
Re-connect the power supply wire ,and
tightly fasten.
The outdoor power supply main circuit
switch locate “OFF” position or fuse
failure of main circuit
Dial the power supply switch to “ON ”
position or change the fuse and make sure
the main touch point of AC Contactor
have current go through
Condenser fan and
compressor don’t run
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.
