Service manual

3-3
AY-ZP35PR
Function Operation Self-diagnosis result
display
Description Detection period Reset condition Indoor
unit error
display
Indoor unit Outdoor
unit
29 PAM clock error When power source frequency
cannot be determined (at start-
up), or when power source clock
cannot be detected for 1 contin-
uous second (at startup).
At compressor startup,
when in operation
Compressor continues
operation without stop-
ping.
None Yes Yes
ڏ
1—A single error judgment results in the display of the indoor unit error (complete shutdown).
ڏ
2—The outdoor unit restarts four times before the indoor unit error is displayed (complete shutdown).
ڏ
3—The outdoor unit restarts eight times before the indoor unit error is displayed (complete shutdown).
[2] AIR TO AIR HEAT PUMP OPERATION IN THERMISTOR ERROR
1. Indoor unit
Item Mode Control opera-
tion
When resistance
is low (tempera-
ture judged high-
er than actual)
Short-circuit When resistance
is high (tempera-
ture judged lower
than actual)
Open-circuit
Room temperature
thermistor (TH1)
Auto Operation mode
judgment
Cooling mode is ac-
tivated even if room
temperature is low.
Cooling mode is acti-
vated in most cases.
Heating mode is ac-
tivated even if room
temperature is high.
Heating mode is
always activated.
Cooling Frequency control Room becomes too
cold.
Air/air heat pump
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 memo-
ry as 31.0°C, and
compressor does
not stop.
Normal operation. Room temperature
is stored in memo-
ry as 18.5°C, and
compressor does
not operate.
Heating Frequency control Room does not
become warm.
Hot keep status
results immediate-
ly after operation
starts.
Frequency does not
increase above 30
Hz (40 Hz).
Room becomes too
warm.
Air/air heat pump
operates in full
power even when
set temperature is
reached.
Heat exchanger
thermistor (TH2)
Cooling
Dehumidifying
Freeze prevention Indoor unit evapora-
tor may freeze.
Indoor unit evapora-
tor may freeze.
Compressor stops
occasionally.
Compressor does
not operate.
Heating Cold air prevention Cold air prevention
deactivates too soon
and cold air dis-
charges.
Compressor oper-
ates at low speed or
stops, and frequency
does not increase.
Cold air prevention
deactivates too slow.
Cold air prevention
does not deactivate,
and indoor unit fan
does not rotate.