IVT 12PHR-N - Air Conditioner Operation in Thermistor Error

3-3
12PHR-N
Function Operation Self-diagnosis result
display
Description Detection period Reset condition Indoor
unit error
display
Indoor
unit
Outdoor
unit
23 Outdoor unit
discharge
thermistor open-
circuit error
Compressor stops if there is
open-circuit in outdoor unit
discharge thermistor (TH1).
At compressor startup Operation OFF or ON
Yes
☆
1
Yes Yes
24 Serial signal
error
Compressor stops if outdoor
unit cannot receive serial
signal from indoor unit for 30
seconds.
When in operation Reset after reception of
serial signal
None None None
25 Compressor
startup
error
Compressor stops if
compressor
At compressor startup Operation OFF or ON
Yes
☆
3
Yes Yes
26 Compressor
rotation error (at
120° energizing)
Compressor stops if there is no
input of position detection sig-
nal from compressor or input is
abnormal.
Compressor operating
at 120° energizing
Operation OFF or ON
Yes
☆
3
Yes Yes
27 Outdoor unit DC
fan error
Operation stops if there is no
input of rotation pulse signal
from outdoor unit fan motor for
30 seconds.
When outdoor unit fan
is in operation
Operation OFF or ON
Yes
☆
1
Yes Yes
28 PAM over
voltage error
Compressor stops if DC
voltage is 400 V or higher.
When in operation Operation OFF or ON
Yes
☆
2
Yes Yes
29 PAM clock error When power source frequency
cannot be determined (at
startup), or when power source
clock cannot be detected for 1
continuous second (at startup).
At compressor startup,
when in operation
Compressor continues
operation without
stopping.
None Yes Yes
☆
1—A single error judgment results in the display of the indoor unit error (complete shutdown).
☆
2—The outdoor unit restarts four times before the indoor unit error is displayed (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 Control operation When resistance
is low (temperat-
ure judged higher
than actual)
Short-circuit When resistance
is high (temperat-
ure judged lower
than actual)
Open-circuit
Room temperature
thermistor (TH1)
Auto Operation mode
judgment
Cooling mode is
activated even if
room temperature
is low.
Cooling mode is
activated in most
cases.
Heating mode is
activated even if
room temperature
is high.
Heating mode is
always activated.
Cooling Frequency control Room becomes too
cold.
Air conditioner
operates in full
power even when
set temperature is
reached.
Room does not
become cool.
Compressor does
not operate.
Dehumidifying Room temperature
memory Frequency
control
Normal operation. Room temperature
is stored in memory
as 31.0°C, and
compressor does
not stop.
Normal operation. Room temperature
is stored in memory
as 18.5°C, and
compressor does
not operate.
Heating Frequency control Room does not
become warm.
Frequency does
not increase above
30 Hz (40 Hz).
Room becomes too
warm.
AIR CONDI-
TIONER operates
in full power even
when set temperat-
ure is reached.
Heat exchanger
thermistor (TH2)
Cooling
Dehumidifying
Freeze prevention Indoor unit evapor-
ator may freeze.
Indoor unit evapor-
ator may freeze.
Compressor stops
occasionally.
Compressor does
not operate.
12PHR-N_S530612PHRN.indd 3 2013/8/7 15:42:14