Hitachi RAS-4.0PNNBDH1 - Overload in Cooling Mode Causes and Solutions; Overload in Heating Mode Causes and Solutions

2. TROUBLESHOOTING
NOTE 1:
If the indoor unit c
an not start or the
indoor unit stops
itself after 30s, at the same time the unit
do
not display the fault code, please check the fire and the socket of the control board.
NOTE 2
:
If the
indoor unit displays
the 75,76,77,
78 fault c
ode after y
ou turn
on the unit, please c
heck the
TEST s
eat of the indoor control board or the TEST detection circuit to see whether short circuit
occurs.
NOTE 3: Overload in cooling mode
Overload in cooling mode
sr. The root cause Corrective measure
1
The refrigerant is
excessive
.
Discharge the refrigerant, and recharge
the refrigerant referring to the rating label.
2
The outdoor ambient tem
perature is
to
o high
.
Please us
e it within
allowabl
e temperatur
e range
3
S
hort-circuit
occurs in the air outlet and air inlet of
the outdoor unit
.
Adjust the installation of the outdoor unit
referring to the user m
anual.
4
The outdoor heat ex
c
hanger is
dirty,
suc
h
as
condenser
.
Clean the heat exchanger of the outdoor unit,
s
uch as c
ondenser.
5
The speed of the outdoor fan motor is too low. Check the outdoor fan m
otor a
nd fan
capacitor
.
6
The outdoor fan is broken or the outdoor fan
is blocked.
Check the outdoor fan.
7
The air inlet and outlet have been blocked. Remove the obstacles.
8
The expansion v
alve or the
capillary
fail
s. Replace the ex
pansion v
alve or
t
he capillary
.
NOTE 4: Over load in heating mode
Overload in heating mode
sr. The root cause Corrective measure
1
The refrigerant is
excessive
.
Discharge the r
efrigerant, and r
echarge
the refrigerant refer
ring
t
o th
e rati
ng label
.
2
The indoor ambient tem
perature is
t
oo high
. Please us
e within
allowabl
e temperatur
e r
ange.
3
Short-circuit occurs in the air outlet and air
inlet of the indoor unit.
A
djust the
installati
on of
th
e indoor
unit
refer
ring
t
o the user
manual
.
4
The indoor filter is dirty. Clean the indoor filter.
5
The speed of the indoor fan motor is
to
o low
.
Check the indoor fan motor and fan capacitor.
6
The indoor fan is broken or the outdoor fan
is blocked.
Check the indoor fan.
7
The air inlet and outlet have been blocked. Remove the obstacles.
8
The expansion v
alve or the
capillary
fail
s. Replace the expansion v
alve or t
he capillary
.
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