7. FUNCTIONS

7-1. Explanation of Functions

NOTE The numerical values such as temperature, frequency, time and current in parentheses are an example

of CU-4KE31NBU and the values are different from the other models.

 

Control/conditions

 

Unit operation

Explanation

 

 

 

 

 

 

INITIAL Breaker is ON.

 

 

 

Power is supplied to the indoor and outdoor unit

 

 

 

 

 

control circuits, however the unit remains stopped.

 

 

 

 

 

Positioning of the outdoor unit electric expansion

 

 

 

 

 

valve is performed.

 

 

 

 

 

 

 

The ON/OFF operation

If automatic operation mode has been selected

This applies in the case of automatic

 

button on the remote

with the remote controller, operation begins in

HEAT/COOL operation.

 

controller is pressed.

HEAT, SENSOR DRY, or COOL mode

 

 

 

depending on the room temperature and

 

 

 

outdoor temperature at the time operation starts.

 

 

 

 

 

 

 

 

 

 

 

Depending on the operational mode, refer to the HEAT, SENSOR DRY, or COOL item.

 

 

 

 

 

 

HEAT

The ON/OFF operation

 

 

Operation lamp illuminates.

The unit is forced to stop for 3 minutes after

 

button on the remote

 

 

Indoor fan is stopped to prevent cold air from

the power is turned ON, or 3 minutes after the

 

controller is pressed.

 

 

compressor stops, in order to protect the

 

 

 

being emitted.

 

 

 

 

compressor.

 

 

 

 

Outdoor unit begins operating after

 

 

 

 

The frequency is increased at the rate of 1 Hz

 

 

 

 

forced-stop is canceled.

 

 

 

 

every 0.5 seconds.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When the indoor coil temperature rises,

Depending on the relationship between the

 

 

 

 

the compressor starts,

remote controller temperature setting and the

 

 

 

 

room temperature, the compressor may stop

 

 

 

 

the outdoor fan starts,

 

 

 

 

temporarily (in other words, the thermostat

 

 

 

 

and the indoor fan changes from "LL"

 

 

 

 

may turn OFF).

 

 

 

 

 

 

 

 

to the set fan speed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When the frequency reaches Hz,frequency

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

 

 

 

increases are stopped for a period of seconds.

compressor.

 

 

 

(Refor to Table 2 "Freguency control".)

 

 

 

 

 

 

 

 

 

 

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 remote

Operating frequency is stabilized in order to

 

has reached the desired

 

 

controller temperature setting are

maintain a comfortable environment.

 

temperature.

 

 

approximately equal.

 

 

 

 

 

 

 

 

The thermostat turns

 

 

The indoor fan is stopped.

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

 

OFF.

 

 

 

thermostat for another indoor unit is ON.)

 

 

 

 

 

Approximately 30 seconds after the

 

 

 

 

 

thermostat turns OFF, the indoor fan is

 

 

 

 

 

stopped.

 

 

 

 

 

 

 

The indoor and outdoor

 

In order to protect the compressor, the outdoor

The outdoor unit starts automatically after 3

 

temperatures are high.

 

unit will not operate for 3 minutes after the

minutes.

 

 

 

thermostat turns OFF, even if the room

During these 3 minutes, a low-pressure

 

 

 

temperature drops below the desired

 

 

 

pressure balance is achieved, allowing the

 

 

 

temperature.

 

 

 

compressor to start more easily.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The frequency is not increased, even if

The amount of heat pump exceeds the amount

 

 

 

 

there is a difference between the room

of heat radiation from the room.

 

 

 

 

temperature and the desired temperature.

Therefore, there is no need to further increase

 

 

 

 

In some cases, the frequency may be

the compressor capacity, and the frequency is

 

 

 

 

decreased.

stabilized or lowered.

 

 

 

 

 

 

71

Page 71
Image 71
Panasonic CU-3KE19NBU, CU-4KE31NBU, CU-4KE24NBU service manual Explanation of Functions

CU-3KE19NBU, CU-4KE24NBU, CU-4KE31NBU specifications

The Panasonic CU-4KE24NBU, CU-4KE31NBU, and CU-3KE19NBU are high-efficiency air conditioning units that represent Panasonic's commitment to innovative climate control solutions. These models integrate advanced technologies to deliver superior performance, energy savings, and user comfort, making them ideal for both residential and commercial applications.

The CU-4KE24NBU, a part of the ECOi series, is designed for medium-sized spaces. It boasts an impressive cooling capacity, ensuring optimal temperature regulation. Its inverter technology adjusts the compressor speed according to the needs of the environment, resulting in reduced energy consumption and consistent comfort levels. The unit operates quietly, making it suitable for bedrooms, offices, or other noise-sensitive environments. Additionally, it features a robust air filtration system that improves indoor air quality by removing dust and allergens.

The CU-4KE31NBU offers a slightly higher capacity, making it perfect for larger areas. Like its counterpart, it utilizes inverter technology, which not only enhances energy efficiency but also minimizes wear and tear on the components, leading to a longer lifespan. Its multi-split capability allows for the connection of multiple indoor units to a single outdoor unit, providing flexibility in installation. The CU-4KE31NBU also integrates smart technology that allows users to control the system remotely via smartphones, giving them greater convenience and control over their environment.

For applications requiring a more compact option, the CU-3KE19NBU is an excellent choice. This model balances size and power, offering a competitive cooling capacity that can easily service small to medium-sized rooms. The unit is designed for easy installation and maintenance, featuring a lightweight construction that simplifies handling by technicians. The efficient inverter technology ensures that users benefit from lower energy bills while maintaining a consistent indoor climate.

All three models are equipped with Panasonic’s advanced refrigerants, which contribute to their eco-friendly performance. These refrigerants help reduce greenhouse gas emissions while maintaining high efficiency. Moreover, the units come with built-in diagnostic capabilities, allowing for quick detection of any issues, thus ensuring that the systems operate at peak efficiency throughout their lifespan.

In summary, the Panasonic CU-4KE24NBU, CU-4KE31NBU, and CU-3KE19NBU are exemplary air conditioning solutions that combine cutting-edge technology with user-friendly features, ensuring that they meet the varying needs of today's consumers while promoting energy efficiency and sustainability.