Grandaire 4860 - Page 30

30
Check whether refrigerant
amount is correct according to
subcooling in charge mode
(force mode)
Check whether indoor unit is
normal by valve, filter and
airflow
Exclude indoor unit fault
reasons and restart
Check whether indoor unit and
outdoor unit are normal by
valve, filter and airflow
Exclude all fault reasons
and restart
H6/P4 (High discharge temperature(T5) protection of compressor)
Diagnosis
Handling
Yes
Check whether discharge temp.
sensor T5 resistance is normal,
refer to TABLE2
Yes
Check whether position of
discharge temp. sensor is
correct. whether there’re other
heat sources around
Yes
Whether compressor is
normal（abnormal noise，
abnormal vibration）
Yes
No
In heating mode,check whether
compressor gas return pressure
is lower than 30 PSIG
No
Replace the compressor
discharge temp. sensor
No
Troubleshooting
problems and restart
No
Adjust Refrigerant
Charge
Yes
Replace compressor
No
Replace EXV (valve
sticking)
Replace the main control
board
Yes
No
HH/PH (low discharge superheat protection)
Diagnosis Handling
Check whether T3/T5/
Pressure Transducer are
normal according to Table1,
Table 2 and Table3
Check whether T3/
Pressure Transducer are
normal according to Table1
and Table3
Yes
Yes
In cooling mode,check whether
the suction superheat is
correct
Yes
In heating mode, check whether
outdoor fan is normal,outdoor
unit is blocked
Yes
Restart and heating, after 45min,
check whether the ODU EXV
action is normal (If discharge
superheat was lower than target
value, EXV opening will get
smaller.Otherwise EXV opening
will be bigger.)
Replace sensors
Replace sensors
No
No
1.Not applicable for piston
2.Adjust the TXV superheat
3.To further adjust TXV swich to
SW4-4”ON”
No
Replace the main
control board
No
Troubleshoot outdoor
fan (replace the motor
or fan)
No
Replace outdoor EXV
Yes
CE/P1 (High pressure switch(HPS) protection)
Diagnosis Handling
Yes
Check whether high pressure
switch is close
Yes
Yes
Cooling mode refers to F3/P5
Heating mode refers to F5/Hb
No
Replace high pressure
switch
No
Yes
Check whether the service
valves are open
Open the service valve
Check whether the service
valves are open
Open the service valve
C6/Pc (Reversing valve fault protection)
Diagnosis Handling
Yes
No
No
Yes
Check whether the running
mode is normal (heating mode
for Heat Pump)
Change mode to heating
Replace the winding of the
reversing valve
Restart to Check whether
there’s the same fault
Replace the reversing valve
Check whether the voltage
between R,V is 24V
Replace the main control
board
No
No
No Further Action
Yes
Yes