Panasonic CS-A7DKD / CU-A7DKD / CS-A9DKD / CU-A9DKD / CS-A12DKD / CU-A12DKD Service Manual ▷ View online
(For 8.5.8. to 8.5.14. information applies only to Heating Operation)
8.5.7. Anti-Dew Formation Control
•
Purpose is to prevent dew formation on indoor unit air discharge area.
•
When room temperature is constant (±1°C) the following conditions occur for 30 minutes continuously, anti-dew formation will
activate:
activate:
−
Remote Control setting temperature is less than 25°C.
−
Compressor is on.
−
Cooling operation mode.
−
Indoor Fan motor operate at Low fan speed (CLo, Lo- or QLo).
•
This control is cancelled immediately when above condition is changed, or Powerful button is pressed.
•
Anti-Dew formation is control by:
1. CLo fan is changed to HLo fan.
2. QLo fan is changed to HLo fan.
1. CLo fan is changed to HLo fan.
2. QLo fan is changed to HLo fan.
8.5.8. 30 Minutes Time Save Control
•
The compressor will start automatically if it has stopped for 30 minutes and the intake air temperature falls between the
compressor OFF temperature (A) and compressor ON temperature (B) during the period.
compressor OFF temperature (A) and compressor ON temperature (B) during the period.
•
This is to maintain the room temperature as set. Despite of this, it is to prevent a wrong judgement of intake air temperature due
to poor installation near the sensor area.
to poor installation near the sensor area.
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8.5.9. Compressor Overload Protection Control
Outdoor Fan Control
•
If the temperature of the indoor heat exchanger rises to 51°C, outdoor fan stops. The outdoor fan restarts when the indoor
heat exchanger temperature falls to 49°C.
heat exchanger temperature falls to 49°C.
Compressor high pressure protection
•
If the indoor heat exchanger becomes 65°C or more, the compressor will stop and restart automatically.
(Time Delay Safety Control - 4 minutes waiting).
(Time Delay Safety Control - 4 minutes waiting).
•
This is to reduce the pressure, as to reduce the indoor heat exchanger temp. Nevertheless, is to protect the compressor
from overload of too high temperature.
from overload of too high temperature.
8.5.10. 4-Way Valve Control
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4-way valve always on during Heating operation. (except deicing operation)
•
When the unit is switched off by remote control during Heating operation, the 4-way valve stay at Heating position for 5 minutes.
•
This is to prevent the refrigerant flow process sound for being occur.
8.5.11. Outdoor Fan Motor Control
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When compressor stops (reaches room temperature), outdoor fan will operate for 30 seconds (forced operation).
•
This is to release the heat and to obtain the lowest pressure as fast as possible.
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8.5.12. Hot Start Control
•
Hot Start Control is to prevent cool air discharge into the room when heating operation start.
•
When Heating operation starts, Indoor fan will not start until the indoor heat exchanger reaches 30°C as diagram shown.
•
Hot start is completed when indoor heat exchanger rises to 39°C or operation over 4 minutes.
8.5.13. Anti Cold Draft Control
•
This operation is to prevent the Cold Draft during Heating mode operation.
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The operation will start when compressor OFF (Thermo OFF) during Heating operation.
•
For the first 30 sec. from compressor OFF (Thermo OFF), Indoor fan speed will operate accordingly to the Indoor heat
exchanger temperature as shown below:
exchanger temperature as shown below:
•
After 30 sec. from compressor OFF (thermo OFF), Indoor fan will run at SSLo speed only.
•
Anti Cold Draft Control will stop when:
−
Intake temperature < set temperature. (Time Delay Safety Control 4 minutes waiting is valid)
−
30 Minutes Time Save Control activates.
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8.5.14. Deicing Control
Deice starts to prevent frosting at outdoor heat exchanger.
•
Normal Deicing
Deice operations detection commences after 30 minutes of Heating operation starts or 60 minutes after previous deice
operation. If the TRS (Thermal Reed Switch) senses the outdoor piping temperature drops to -3°C (TRS CLOSE) or less for
50 sec. continuously during compressor is in operation, deice will start.
(There is no detection during Outdoor Fan stops.)
Deice operations detection commences after 30 minutes of Heating operation starts or 60 minutes after previous deice
operation. If the TRS (Thermal Reed Switch) senses the outdoor piping temperature drops to -3°C (TRS CLOSE) or less for
50 sec. continuously during compressor is in operation, deice will start.
(There is no detection during Outdoor Fan stops.)
•
Overload Deicing
During heating operation, if the outdoor Fan OFF duration (due to overload control) is accumulated up to 60 minutes and
after compressor starts for 1 minutes, deicing starts.
During heating operation, if the outdoor Fan OFF duration (due to overload control) is accumulated up to 60 minutes and
after compressor starts for 1 minutes, deicing starts.
•
Deicing ends when
1. 12 minutes after deicing operation starts;
2. TRS senses the outdoor piping temperature rises to 4°C (TRS OPEN).
1. 12 minutes after deicing operation starts;
2. TRS senses the outdoor piping temperature rises to 4°C (TRS OPEN).
Deicing will not end immediately as time delay (Td) is valid as shown below.
•
Once deicing operation starts, it will not end for 60 seconds.
•
After deicing operation, compressor stops for 30 seconds and 4-way valve stays at cooling position for 10 seconds.
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