IVT AY-XP12FR-N Service Manual page 24

AYXP12FRN
Item Mode
Heat exchanger Cooling
thermistor (TH2) Dehumidifying
Heating
2. Outdoor unit
Item Mode
Compressor Cooling
chamber ther- Dehumidifying
mistor (TH1) Heating
Heat exchanger Cooling
thermistor (TH2) Dehumidifying
Heating
Outside air tem- Auto
perature ther-
mistor (TH3)
Cooling
Dehumidifying
Heating
Suction pipe ther- Cooling
mistor (TH4) Dehumidifying
Heating
Control opera- When resis-
tion tance is low
(temperature
judged higher
than actual)
Freeze preven- Indoor unit evap-
tion orator may
freeze.
Cold air preven- Cold air preven-
tion tion deactivates
too soon and cold
air discharges.
Control opera- When resis-
tion tance is low
(temperature
judged higher
than actual)
Expansion valve Compressor
control and com- operates, but
pressor protection room does not
become cool or
warm (expansion
valve is open).
Outdoor unit heat Compressor
exchanger over- operates at low
heat prevention speed or stops.
Expansion valve Defrosting opera-
control tion is not acti-
Defrosting vated as needed,
and frost accumu-
lates on outdoor
unit (expansion
valve is closed).
Operation mode Cooling mode is
judgment activated even if
room tempera-
ture is low.
Operation not Normal operation.
affected
Rating control Defrosting opera-
Defrosting tion is activated
unnecessarily.
Expansion valve Compressor
control operates, but
room does not
become cool
(expansion valve
is open).
Expansion valve Compressor
control operates, but
room does not
become warm
(expansion valve
is open).
3 – 4
Short-circuit When resis-
tance is high
(temperature
judged lower
than actual)
Indoor unit evap- Compressor
orator may stops occasion-
freeze. ally.
Compressor Cold air preven-
operates at low tion deactivates
speed or stops, too slow.
and frequency
does not
increase.
Short-circuit When resis-
tance is high
(temperature
judged lower
than actual)
Compressor high Layer short-cir-
temperature error cuit or open-cir-
indication. cuit may result in
compressor in
normal operation.
Outdoor unit ther- Normal operation.
mistor short-cir-
cuit error
indication.
Outdoor unit ther- Defrosting opera-
mistor short-cir- tion is activated
cuit error unnecessarily,
indication. and room does
not become warm
(expansion valve
is open).
Outdoor unit ther- Heating mode is
mistor short-cir- activated even if
cuit error room tempera-
indication. ture is high.
Outdoor unit ther- Normal operation.
mistor short-cir-
cuit error
indication.
Outdoor unit ther- Defrosting opera-
mistor short-cir- tion is not acti-
cuit error vated, and frost
indication. accumulates on
outdoor unit.
Outdoor unit ther- Frost accumu-
mistor short-cir- lates on evapora-
cuit error tor inlet section,
indication. and room does
not become cool
(expansion valve
is closed).
Outdoor unit ther- Frost accumu-
mistor short-cir- lates on expan-
cuit error sion valve outlet
indication. section, and room
does not become
warm (expansion
valve is closed).
Open-circuit
Compressor does
not operate.
Cold air preven-
tion does not
deactivate, and
indoor unit fan
does not rotate.
Open-circuit
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.
Outdoor unit ther-
mistor open-cir-
cuit error
indication.