Outdoor heat

 

exchanger temperature (°F)

 

(- 4)

0

Outdoor air

temperature (°F)

 

 

 

 

(21.2)

 

 

(19.4)

L2

 

(-11.2)

L1

 

(-13.0)

Temperature of releasing

Defrost operation time

Less than 2 minutes

2 minutes or more

 

 

 

Heat exchanger

 

 

temperature for

No releasing

57.2 °F or higher (*1)

releasing defrosting

 

 

 

 

 

*1 The temperature for releasing of defrosting is (68 °F) or higher when the outdoor air temperature is less than 32 °F.

 

Fig. 1

 

 

 

Table 1

 

 

 

 

 

 

 

 

 

Control/conditions

 

Unit operation

 

Explanation

 

 

 

 

 

 

 

 

COOL

The ON/OFF operation

The operation lamp illuminates.

The outdoor unit does not operate for 3 minutes

 

button on the remote

The indoor fan operates at the set fan speed.

even after the breaker is turned ON.

 

controller is pressed.

 

 

 

 

The outdoor unit stops.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The outdoor unit starts.

The frequency is increased at the rate of 0.5

 

 

 

 

 

Hz every 1 seconds.

 

 

(Compressor and the outdoor fan start.)

 

 

 

 

 

 

 

 

 

 

 

 

 

When the frequency reaches Hz,

This is in order to stabilize the return of oil to the

 

 

frequency increases are stopped for a period

compressor.

 

 

of seconds. (Refer to Table 2.)

 

 

 

 

 

 

 

 

 

 

 

 

 

The frequency then increases.

If the indoor and outdoor temperatures are high,

 

 

 

 

 

the current peak cut-off activates, stopping

 

 

 

 

 

any increases in frequency.

 

 

 

 

 

 

 

 

 

The room temperature

The indoor temperature and the desired

Operating frequency is stabilized in order to

 

has reached the

temperature are approximately equal.

maintain a comfortable environment.

 

desired temperature.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The thermostat turns

 

 

 

The outdoor unit stops. (It does not stop if the

 

OFF.

 

 

 

thermostart for another indoor unit is ON.)

 

 

 

 

 

 

 

 

 

The thermostat turns

After the thermostat turns ON again, the

After 3 minutes, the outdoor unit begins operating

 

ON again.

outdoor unit will not operate for 3 minutes,

automatically.

 

 

even if the room temperature increases

During these 3 minutes, a pressure balance is

 

 

above the desired temperature.

 

 

achieved, allowing the compressor to start

 

 

 

 

 

 

 

 

 

 

more easily.

 

 

 

 

 

 

 

 

 

Freeze prevention

When the temperature of the indoor heat

In order to protect against freezing, the

 

 

exchanger drops to approximately 35.6 °F

compressor stops temporarily, until the

 

 

or below, the compressor turns OFF, the

temperature of the indoor heat exchanger has

 

 

outdoor fan turns OFF, and the indoor fan

risen.

 

 

continues operating with no changes.

 

 

 

 

 

Approximately 3 minutes later, if the

 

 

 

 

 

temperature of the indoor heat exchanger

 

 

 

 

 

is adove 46.4 °F, the system returns to its

 

 

 

 

 

original conditions.

 

 

 

 

 

 

 

 

 

 

 

 

Stop

All indicator lamps turn OFF. The indoor and

 

 

 

 

 

outdoor units stop.

 

 

 

 

 

 

 

 

 

 

 

 

Operation is restarted

Starts operating in the same operating mode

Within 4 hours after operation was stopped, it is

 

within 4 hours (only when

(COOL) and with the same temperature

assumed that there has been no significant

 

AUTO mode is selected

settings as before operation was stopped.

change in the indoor and outdoor temperatures,

 

with the remote

 

 

 

and the previous conditions (COOL) are stored.

 

controller).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Operation starts after 4

New operating mode is determined based on

 

 

 

 

hours or more have

the temperature conditions at the time the

 

 

 

 

 

 

 

 

passed.

ON/OFF operation button is pressed.

 

 

 

 

 

 

 

 

 

 

 

73

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Panasonic CU-4KE24NBU, CU-4KE31NBU, CU-3KE19NBU service manual Cool

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