Panasonic CU-4E27PBD / CU-5E34PBD Service Manual ▷ View online
33
12. Simultaneous Operation Control
Operation modes which can be selected using the remote control unit:
o
Automatic, Cooling, Dry, Heating and e-ion operation mode.
Types of operation modes which can be performed simultaneously
o
Cooling operation and Cooling, Dry or e-ion operation.
o
Heating operation and Heating operation.
Types of operation modes which cannot be performed simultaneously
o
During cooling operation, heating operation is impossible at another indoor unit in another room.
o
The priority is given to cooling operation if the cooling mode is selected first. In another room where heating
mode is selected afterward, the POWER LED blinks to indicate the heating operation is in standby condition,
where the fan is stopped hence no discharged air.
where the fan is stopped hence no discharged air.
o
During heating operation, cooling operation is impossible at another indoor unit in another room.
o
The priority is given to heating operation if the heating mode is selected first. In another room where cooling
mode is selected afterward, the POWER LED blinks to indicate the cooling operation is in standby condition,
where the fan is stopped hence no discharged air.
where the fan is stopped hence no discharged air.
Operation mode priority control
o
The operation mode designated first by the indoor unit has priority.
o
If the priority indoor unit stops operation or initiates the fan operation, the priority is transferred to other indoor
units.
“Waitin
g” denotes the standby status in which the POWER LED blinks (ON for 2.5 seconds and OFF for 0.5 seconds)
and the fan is stopp
ed.
In the e-ion mode, priority is transferred to a non-priority unit.
Note
C: Cooling operation mode
D: Dry operation mode
H: Heating operation mode
E: e-ion operation mode
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13. Protection
Control
13.1 Freeze Prevention Control (Cool)
When received freeze prevention signal from indoor unit, the compressor frequency changes according to indoor
heat exchanger temperature.
When indoor unit request capability OFF due to freeze condition, immediately the capability supply to targeted
indoor unit stops.
13.2 Dew Prevention Control (Cool)
When received dew prevention signal from indoor unit, which according to indoor intake temperature and indoor
heat exchanger temperature the compressor frequency changes.
13.3 Electronic Parts Temperature Rise Protection 1 (Cool)
This control prevents electronic parts temperature rise during cooling overload condition.
Start
conditions:
o
Outdoor ambient temperature is at protection region as shown in figure below:
o
Outdoor unit total current is above 5.0A.
Control
content
o
Outdoor fan speed is adjusted accordingly.
Control
stop
condition
o
When outdoor ambient temperature is back to normal region.
During this control, outdoor fan speed does not reduce for Quiet operation.
13.4 Electronic Parts Temperature Rise Protection 2 (Cool)
This control prevents electronic parts temperature rise during cooling/dry operation.
Start
conditions:
o
Total current is at protection region as shown in figure below:
Control
content
o
Outdoor fan speed is adjusted accordingly.
Control
stop
conditions
o
When total current is back to normal region.
During this control, outdoor fan speed does not reduce for Quiet operation.
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13.5 Cooling Overload Control (Cool)
This control detect outdoor pipe temperature and perform the compressor frequency restriction during cooling
operation.
13.6 Heating Overload Control (Heat)
This control detect indoor pipe temperature and perform the compressor frequency restriction during heating
operation.
This control detect outdoor ambient temperature and perform the fan speed adjustment during heating operation.
13.7 Extreme Low Temperature Compressor Low Pressure Protection
Control (Heat)
This control is to prevent low pressure drops too low during extremely low outdoor ambient temperature to
improve the compressor reliability.
During heating operation, when outdoor ambient temperature is in Zone 1, this control will be activated.
Compressor frequency restriction will be based on outdoor piping temperature.
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13.8 Deice Control
When outdoor pipe temperature and outdoor air temperature is low, deice operation starts where indoor fan
motor and outdoor fan motor stop, indoor unit horizontal vane close and operation LED blink with compressor ON.
13.9 Time Delay Safety Control (Restart Control)
The compressor will not restart within three minutes after compressor is stopped.
This control is not applicable if the power supply reset or after deice condition.
13.10 30 seconds Force Operation
Once the compressor starts operation, it will not stop its operation for 30 seconds in order to cycle back
compressor oil.
However, it can be stopped using remote control or Auto OFF/ON button at indoor unit.
13.11 Total Current Control
By referring to table below, during normal (default) operation, the running current refer to Hi values and during
Power Save Mode, the running current refer to Lo values.
When the outdoor unit total running current (AC) exceeds X value, compressor frequency will decrease.
If the running current does not exceed X value for 5 seconds, compressor frequency will increase.
However, if total outdoor unit running current exceeds Y value, compressor will be stopped immediately for
3 minutes.
Operation Mode
CU-4E27PBD CU-5E34PBD
X (A)
Y (A)
X (A)
Y (A)
Cooling/Soft Dry (A)
Hi 14.0 17.5 14.0 17.5
Lo 9.8 17.5 9.8 17.5
Cooling/Soft Dry (B)
Hi 14.0 17.5 14.0 17.5
Lo 9.8 17.5 9.8 17.5
Heating
Hi 14.0 17.5 14.0 17.5
Lo 9.8 17.5 9.8 17.5
13.12 IPM (power transistor) Protection Control
Overheating Prevention Control
o
If IPM temperature rises to 80°C, outdoor fan speed will be increased.
o
When the IPM temperature rises to 95°C, compressor operation will stop immediately.
o
Compressor operation restarts when temperature decreases to 90°C.
o
If IPM temperature detected less than -30°C, IPM is judged as open circuit (“F96” is indicated).
DC peak current control
o
When IPMDC current exceeds set value of 30.0 ± 3.0 A, the compressor will stop.
o
If the DC peak current detected within 30 seconds after operation starts, compressor will restart after
1 minute.
o
If the DC peak current detected 30 seconds or more after operation starts, compressor will restart after
2 minutes.
o
Within 30 seconds after compressor restarts, if the DC peak current is exceeded set value continuously for
7 times, all indoor and outdoor relays will be cut off (“F99” is indicated).
Error reset can be done by power supply reset.
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