IVT 09LR-N Service Manual page 26

12LRN
2. Outdoor unit
Item Mode
Compressor cham- Cooling
ber thermistor Dehumidifying
(TH1) Heating
Heat exchanger Cooling
thermistor (TH2) Dehumidifying
Heating
Outside air temper- Auto
ature thermistor
(TH3)
Cooling
Dehumidifying
Heating
Suction pipe ther- Cooling
mistor (TH4) Dehumidifying
Heating
2-way valve ther- Cooling
mistor (TH5) Dehumidifying
Heating
Control operation When resistance
is low (tempera-
ture judged higher
than actual)
Expansion valve Compressor oper-
control and com- ates, but room does
pressor protection not become cool or
warm (expansion
valve is open).
Outdoor unit heat Compressor oper-
exchanger over- ates at low speed
heat prevention or stops.
Expansion valve Defrosting opera-
control tion is not activated
Defrosting as needed, and
frost accumulates
on outdoor unit
(expansion valve is
closed).
Operation mode Cooling mode is
judgment activated even if
room temperature
is low.
Operation not Normal operation.
affected
Rating control Defrosting opera-
Defrosting tion is activated
unnecessarily.
Expansion valve Compressor oper-
control ates, but room does
not become cool
(expansion valve is
open).
Expansion valve Compressor oper-
control ates, but room does
not become warm
(expansion valve is
open).
Expansion valve Frost accumulates
control on indoor unit evap-
orator and room
does not become
cool (expansion
valve is closed).
Operation not Normal operation.
affected
3 – 4
Short-circuit When resistance
is high (tempera-
ture judged lower
than actual)
Compressor high Layer short-circuit
temperature error or open-circuit may
indication. result in compres-
sor in normal oper-
ation.
Outdoor unit ther- Normal operation.
mistor short-circuit
error indication.
Outdoor unit ther- Defrosting opera-
mistor short-circuit tion is activated
error indication. unnecessarily, and
room does not
become warm
(expansion valve is
open).
Outdoor unit ther- Heating mode is
mistor short-circuit activated even if
error indication. room temperature
is high.
Outdoor unit ther- Normal operation.
mistor short-circuit
error indication.
Outdoor unit ther- Defrosting opera-
mistor short-circuit tion is not activated,
error indication. and frost accumu-
lates on outdoor
unit.
Outdoor unit ther- Frost accumulates
mistor short-circuit on evaporator inlet
error indication. section, and room
does not become
cool (expansion
valve is closed).
Outdoor unit ther- Frost accumulates
mistor short-circuit on expansion valve
error indication. outlet section, and
room does not
become warm
(expansion valve is
closed).
Outdoor unit ther- Compressor oper-
mistor short-circuit ates, but room does
error indication. not become cool
(expansion valve is
open).
Outdoor unit ther- Normal operation.
mistor short-circuit
error indication.
Open-circuit
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.
Outdoor unit ther-
mistor open-circuit
error indication.