Service manual

3-1
AY-ZP35PR
CHAPTER 3.
FUNCTION AND OPERATION OF PROTECTIVE PROCEDURES
[1] PROTECTION DEVICE FUNCTIONS AND OPERATIONS
Function Operation Self-diagnosis result
display
Description Detection period Reset condition Indoor
unit error
display
Indoor unit Outdoor
unit
1 Indoor unit fan
lock
Operation stops if there is no
input of rotation pulse signal
from indoor unit fan motor for 1
minute.
When indoor unit fan is
in operation
Operation OFF or ON
ۼ
1 Yes None
Indoor unit fan ro-
tation speed error
Operation stops if rotation pulse
signal from indoor unit fan in-
dicates abnormally low speed
(about 300 rpm or slower).
When indoor unit fan is
in operation
Operation OFF or ON
ۼ
1 Yes None
2 Indoor unit freeze
prevention
Compressor stops if temperature
remains below 0°C for 4 min-
utes.
When in cooling or de-
humidifying operation
Automatic reset when
heat exchanger temper-
ature rises above freeze
prevention temperature
(2°C or higher)
- None None
3 2-way valve
freeze prevention
Compressor stops if tempera-
ture of outdoor unit 2-way valve
remains below 0°C for 10 contin-
uous minutes during cooling or
dehumidifying operation.
When in cooling or de-
humidifying operation
Automatic reset when
temperature of 2-way
valve rises above 10°C.
None Yes Yes
4 Indoor unit heat
exchanger over-
heat shutdown
Operating frequency lowers
if indoor unit heat exchanger
temperature exceeds overheat
temperature during heating op-
eration.
Compressor stops if indoor unit
heat exchanger temperature ex-
ceeds overheat temperature for
60 seconds at minimum frequen-
cy.Overheat temperature setting
value indoor unit heat exchanger
thermistor temperature: about 45
to 54°C
When in heating opera-
tion
Automatic reset after
safety period (180 sec).
None Yes Yes
5 Outdoor unit heat
exchanger over-
heat shutdown
Operation frequency lowers if
outdoor unit heat exchanger
temperature exceeds about
55°C during cooling operation.
Compressor stops if outdoor unit
heat exchanger temperature
exceeds about 55°C for 120 sec-
onds at minimum frequency.
When in cooling or de-
humidifying operation
Automatic reset after
safety period (180 sec).
None Yes Yes
6 Compressor dis-
charge overheat
shutdown
Operating frequency lowers
if temperature of compressor
chamber thermistor (TH1) falls
below about 110°C.
Compressor stops if temperature
of compressor chamber ther-
mistor (TH1) remains at about
110°C (for 120 seconds in cool-
ing operation, or 60 seconds in
heating operation) at minimum
frequency.
When compressor is in
operation
Automatic reset after
safety period (180 sec).
None Yes Yes
7 Dehumidifying
operation tempo-
rary stop
Compressor stops if outside air
temperature thermistor is lower
than about 16°C during dehu-
midify-ing operation.
When in dehumidifying
operation
Automatic reset when
outside air temperature
rises above 16°C.
None Yes Yes
8 DC overcurrent
error
Compressor stops if DC current
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IPM.
When compressor is in
operation
Operation OFF or ON Yes
ۼ
2 Yes Yes
9 AC overcurrent
error
Operating frequency lowers if
outdoor AC current exceeds
peak control current value. out-
door stops if compressor AC
current exceeds peak control
current value at minimum fre-
quency.
When compressor is in
operation
Operation OFF or ON Yes
ۼ
2 Yes Yes