DC Inverter Multi VRF System
28
Phenomenon
Causes
Noise is emitted
When the indoor unit stops running,
a faint “sa
——
” sound or “gurgling”
sound can be heard.
This sound can be heard when other indoor units
are running. This is to prevent oil and refrigerant
from staying in the indoor unit, and to keep a small
amount of refrigerant flowing.
When the unit is running, the
operating sound of the compressor
changes.
This is caused by changes in compressor operating
frequency.
During the operation of the unit or
after the operation is started or
stopped, a continuous “sa
——
”
sound can be heard.
This is the sound produced when the refrigerant
bypass valve operates.
When the operating mode of the unit
changes, the indoor unit and outdoor
unit will produce “sa
——
” and
“gurgling” sounds.
This is the sound produced when the refrigerant
stops or changes flow.
The sound from the outdoor unit can
be heard indoors
This is because the outdoor unit is installed close to
the window or wall, and the sound insulation is
poor, and the external noise is transmitted in.
There is dust blowing
out from the unit
Start operation after it is not used for
a long time
Dust in indoor unit is blew out
The unit emits odor
Operating
The odor of the air conditioner is sucked into the
room and then blown out
The indoor unit is still
running after shutting
down
The indoor unit is still running after
shutting down
The fan of indoor unit will continue to work for 20 to
70 seconds to fully use the residual cooling or heat
of the heat exchanger, and to prepare for the next
use.
Mode conflict
Cooling or heating mode cannot start
up
When the selected operation mode of the indoor
unit conflicts with the operation mode of the outdoor
unit, after five seconds, the indoor unit error
indicator flashes or the remote controller displays
the operation conflict, and the indoor unit shuts
down. At this time, the indoor unit can be converted
to run with the outdoor unit. The mode can be
restored to normal without conflict. The cooling
mode and dry mode do not conflict, and the air
supply does not conflict with any mode.
7 Error Indication
Inquiry method of error indication: combine division symbol and content symbol to check the
corresponding error.
For example, division symbol L and content symbol 4 together means over-current protection.
Indoor:
Error Code
Content
Error Code
Content
L0
Malfunction of IDU (uniform)
L1
Protection of indoor fan
L2
Auxiliary heating protection
L3
Water-full protection
L4
Over-current protection
L5
Freeze prevention protection
L6
Mode shock
L7
No main IDU
L8
Power supply is insufficient
L9
1-to-more: number of IDU is inconsistent
LA
1-to-more: IDU series is inconsistent
LH
Alarm due to bad air quality (Fresh air unit)
LC
Models for IDU and ODU are not matched
EC
Drop protection of discharge temperature
sensor of compressor 1
d1
Indoor PCB is poor
d3
Malfunction of ambient temperature sensor
d4
Malfunction of entry-tube temperature
sensor
d5
Malfunction of middle temperature sensor