Mitsubishi Electric FDF71VNXVD Technical Manual page 151

Error code
None
Remote controller:
1. Applicable model
All models
2. Error detection method
3. Condition of Error displayed
4. Presumable cause
• Faulty 4-way valve operation
• Poor compression of
compressor
• Faulty expansion valve
operation
Note:
LED Green Red
Keeps flashing Stays OFF
Indoor
Keeps flashing Stays OFF
Outdoor
5. Troubleshooting
Diagnosis
Check the indoor unit fan operation.
Check the temperature differnce
between return and supply air.
Is the
temperature differnce
between return and supply air
YES
10-30°C at
heating?
NO
Is the compressor
operating?
message is displayed (for 3 seconds) when
performing cooling, defrosting and heating
YES
Is the
compressor rotation
speed low?
YES
Check which control "Determination control of
conpressor rotation speed" or "Protective control
by controlling compressor rotation speed" is
appropriate to this phenomenon.
(1)
Are the
temperature conditions
of room and outdoor air close
to the rated
conditions?
Note (1) Outdoor: 7°C, Indoor: 20°C
NO
The unit is operating normally but is
operating under the contol for protecting
compressor or other respective parts.
150
-
Content
Operates but does not heat
Does the
heat load increase after
installtion?
YES
Mistake in model selection.
Calculate heat load once again.
NO
" "
WAIT
YES
operations from the remote
controller.
NO
NO
YES
-
'11 • PAC-T-160
Countermeasure
It is normal.
(This unit is designed to
start in the soft start mode
by detecting the under
dome temperature of
NO
compressor when it restart
after power reset.
It is necessary to replace to
higher capacity one or to
install additional unit.
Compressor refrigerant oil
protection control at starting
is activated. For the contents
of control, refer to the
compressor start control of
the microcomputer control
functions.
Compressor may be
stopped by the error
detection control.
For the contents of control,
refer to anomalous stop
control by controlling
compressor rotation speed
of microcomputor control
functions.
Inspect the followings.
• Minor clogging of filter
• Minor clogging of heat
exchanger
• Minor short-circuit
• Minor shortage of
refrigerant amount
• Poor compression of
compressor
Considering appropriate
operation control, check
suspicious points.
Inspect the followings for
reference.
• Major clogging of filter
• Major clogging of heat
exchanger
• Major short-circuit
• Major shortage of
refrigerant amount
• Compressor protection ON
• Indoor fan tap
• Valid setting of silent mode