Air Conditioner Operation In Thermistor Error - Sharp AY-XP9LSR Service Manual

AYXP9LSR
Function
25 Compressor star- Compressor stops if compressor
tup error fails to start up.
26 Compressor rota- Compressor stops if there is no
tion error (at 120° input of position detection signal
energizing) from compressor or input is
abnormal.
27 Outdoor unit DC fan Operation stops if there is no
error input of rotation pulse signal from
outdoor unit fan motor for 30 sec-
onds.
28 PAM overvoltage Compressor stops if DC voltage is
error 350 V or higher.
29 PAM clock error When power source frequency
cannot be determined (at startup),
or when power source clock can-
not be detected for 1 continuous
second (at startup).
*1—The outdoor unit restarts four times before the indoor unit error is displayed (complete shutdown).
*2—A single error judgment results in the display of the indoor unit error (complete shutdown).
*3—The outdoor unit restarts eight times before the indoor unit error is displayed (complete shutdown).

[2] AIR CONDITIONER OPERATION IN THERMISTOR ERROR

1. Indoor unit
Item Mode
Room tempera- Auto
ture thermistor
(TH1)
Cooling
Dehumidifying
Heating
Heat exchanger Cooling
thermistor (TH2) Dehumidifying
Heating
Operation
Description Detection period
At compressor star-
tup
Compressor operat-
ing at 120° energizing
When outdoor unit
fan is in operation
When in operation
At compressor star-
tup, when in opera-
tion
Control opera- When resis-
tion tance is low
(temperature
judged higher
than actual)
Operation mode Cooling mode is
judgment activated even if
room tempera-
ture is low.
Frequency control Room becomes
too cold.
Room tempera- Normal operation.
ture memory
Frequency control
Frequency control Room does not
become warm.
Freeze preven- Indoor unit evap-
tion orator may
freeze.
Cold air preven- Cold air preven-
tion tion deactivates
too soon and cold
air discharges.
Reset condition
Operation OFF or ON Yes *3
Operation OFF or ON Yes*3
Operation OFF or ON Yes *1
Operation OFF or ON Yes *1
Compressor contin-
ues operation with-
out stopping.
Short-circuit
Cooling mode is
activated in most
cases.
Air conditioner
operates in full
power even when
set temperature is
reached.
Room tempera-
ture is stored in
memory as
31.0°C, and com-
pressor does not
stop.
Hot keep status
results immedi-
ately after opera-
tion starts.
Frequency does
not increase
above 30 Hz (40
Hz).
Indoor unit evap-
orator may
freeze.
Compressor
operates at low
speed or stops,
and frequency
does not
increase.
3 – 3
Self-diagnosis
result display
Indoor Indoor
unit unit
error
display
Yes
Yes
Yes
Yes
None Yes
When resis- Open-circuit
tance is high
(temperature
judged lower
than actual)
Heating mode is Heating mode is
activated even if always activated.
room tempera-
ture is high.
Room does not Compressor does
become cool. not operate.
Normal operation. Room tempera-
ture is stored in
memory as
18.5°C, and com-
pressor does not
operate.
Room becomes Air conditioner
too warm. operates in full
power even when
set temperature is
reached.
Compressor Compressor does
stops occasion- not operate.
ally.
Cold air preven- Cold air preven-
tion deactivates tion does not
too slow. deactivate, and
indoor unit fan
does not rotate.
Outdoor
unit
Yes
Yes
Yes
Yes
Yes