PANASONIC CU-4E23JBE (02) PDF Document

The PANASONIC CU-4E23JBE uses R410A refrigerant and has specific piping size and length requirements to ensure proper operation.

Refrigerant Piping Sizes:

Liquid side: ø 6.35 t0.8

Gas side: ø 9.52 t0.8 (Note: If the indoor unit is CS-E21*** or CS-XE21***, a ø 12.7 t0.8 gas pipe size must be used with a CZ-MA2P pipe size expander).

Allowable Piping Lengths:

Allowable piping length of each indoor unit: Minimum 3m to Maximum 25m.

Allowable total piping length of all indoor units: 60m or less.

Height difference between indoor and outdoor unit (Outdoor unit located on upper side): 15m or less.

Height difference between indoor and outdoor unit (Outdoor unit located otherwise): 7.5m or less.

Height difference between indoor units (Outdoor unit located on upper side): 7.5m or less.

Height difference between indoor units (Outdoor unit located otherwise): 15m or less.

If the total piping length of all indoor units exceeds the equivalent length of 30m, an additional charge of 20g of R410A refrigerant is required for each additional meter of piping.

When choosing a location for the PANASONIC CU-4E23JBE, follow these guidelines:

1. If an awning is built over the unit to prevent direct sunlight or rain, ensure that heat radiation from the condenser is not obstructed.

2. Avoid areas where animals or plants could be affected by the hot air discharged from the unit.

3. Maintain the required clearance spaces from walls, ceilings, fences, or other obstacles as indicated by the arrows in the installation diagrams.

4. Do not place any obstacles that may cause a short circuit of the discharged air.

5. Ensure the location is strong enough to withstand the weight of the unit and is easy to access for maintenance.

6. Do not install the unit in a location where flammable gas leakage may occur or in a laundry room where water may drip from the ceiling.

To connect the piping for the PANASONIC CU-4E23JBE, follow these steps:

Step 1. Remove the control board cover (resin) from the unit by loosening the three screws.

Step 2. Decide the piping length and cut the pipe using a pipe cutter. Remove any burrs from the cut edge using a reamer, turning the piping end downward to avoid metal powder entering the pipe.

Step 3. Insert the flare nut (located at the valve) onto the copper pipe and make the flare.

Step 4. Align the center of the piping to the valves and tighten the flare nut with a torque wrench to the specified torque settings.

Tightening Torque Table:

1/4 inch [6.35 mm]: 18 Nm (1.8 kgf.m)

3/8 inch [9.52 mm]: 42 Nm (4.3 kgf.m)

1/2 inch [12.7 mm]: 55 Nm (5.6 kgf.m)

5/8 inch [15.88 mm]: 65 Nm (6.6 kgf.m)

3/4 inch [19.05 mm]: 100 Nm (10.2 kgf.m)

Caution: Do not over tighten, as over tightening can cause gas leakage.

When installing the PANASONIC CU-4E23JBE, you must evacuate the air inside the indoor units and pipes using the following procedure:

1. Connect a charging hose with a push pin to the Low side of a charging set and the service port of the gas side 3-way valve.

2. Connect the center hose of the charging set to a vacuum pump.

3. Turn on the power switch of the vacuum pump and confirm the needle in the gauge moves from 0 cmHg (0 MPa) to -76 cmHg (-0.1 MPa). Evacuate the air for approximately ten minutes.

4. Close the Low side valve of the charging set and turn off the vacuum pump. Verify the needle does not move for approximately five minutes.

5. Disconnect the charging hose from the vacuum pump and the service port.

6. Tighten the service port caps of the gas side 3-way valve to a torque of 18 Nm using a torque wrench.

7. Remove the valve caps of both the gas side and liquid side 3-way valves. Set both valves to the OPEN position using a 4 mm hexagonal wrench.

8. Mount the valve caps back onto the gas and liquid side 3-way valves and check for any gas leakages.

The PANASONIC CU-4E23JBE manages different operation modes across multiple rooms with specific priority rules:

1. Operation modes that can be performed simultaneously include Cooling with Cooling, Soft Dry, or e-ion operation, and Heating with Heating operation.

2. Operation modes that cannot be performed simultaneously include Cooling and Heating. If a cooling operation is in progress and a heating operation is requested by another room, the room that started first continues. In the second room, the operation lamp will blink, the attempt to establish heating will be made, but the fan will stay stopped and no air will be discharged.

3. Operation mode priority control: The operation mode designated first by the indoor unit has priority. If the priority indoor unit stops operation or starts e-ion operation, the priority is transferred to other indoor units.

Waiting status: This is denoted when the operation lamp LED blinks (ON for 2.5 seconds and OFF for 0.5 seconds), and the fan is stopped.

To collect refrigerant back into the unit using the pump down process on the PANASONIC CU-4E23JBE, follow these steps:

Step 1. Confirm the valves on both the liquid side and gas side are open.

Step 2. Press the PUMP DOWN button (SW1) on the Service PCB inside the outdoor unit for more than 5 seconds. The cooling operation will run for 15 minutes.

Step 3. Close the liquid side 3-way valve and wait until the pressure gauge indicates 0.01 MPa (0.1 kg/cm2G).

Step 4. Immediately close the gas side 3-way valve and then press the PUMP DOWN button (SW1) again to stop the operation.

The operation will stop automatically after 15 minutes if the PUMP DOWN switch is not pressed again. You must start the operation within 3 minutes after the compressor has stopped.

Test operations for the PANASONIC CU-4E23JBE are managed using the TEST OPERATION button (SW2) on the Service PCB:

Cooling Test: Press the SW2 button for 5 seconds to 10 seconds. LED1 and LED2 will illuminate when the unit shifts into the cooling test operation.

Heating Test: Press the SW2 button for more than 10 seconds. LED1 and LED3 will illuminate when the unit shifts into the heating test operation.

To cancel the test operation, press the SW2 button again.

The PANASONIC CU-4E23JBE can automatically correct wiring errors. Use the following procedure:

1. Confirm that the valves on the liquid side and gas side are open.

2. Press the WIRING CHECK button (SW3) on the Service PCB for more than 10 seconds.

3. The wiring check process will take approximately 20 to 25 minutes. Note that it will not start within 3 minutes of the compressor stopping or if the outdoor temperature is below 5 degrees Celsius.

4. After completion, the Service PCB LEDs will indicate the result:

All LEDs flashing: Automatic correction is impossible.

LED2, 4, 6 and LED3, 5 alternatively flashing: Wiring check is in progress.

LEDs flashing one after another: Automatic correction is completed.

Other patterns: The unit has an abnormality.

5. If automatic correction is impossible, the wiring and piping must be checked manually.

The PANASONIC CU-4E23JBE provides diagnosis codes to identify system malfunctions. Below are common codes and their corresponding issues:

H11: Indoor to outdoor abnormal communication. Check wire terminals and PCB.

H12: Indoor unit capacity unmatched. Ensure the number of indoor units and their total capacity are within limits.

H15: Compressor temperature sensor abnormality. Sensor may be open or short circuited.

H16: Outdoor current transformer (CT) abnormality. Could indicate a faulty outdoor PCB or compressor.

H27: Outdoor air temperature sensor abnormality.

H28: Outdoor heat exchanger temperature sensor 1 abnormality.

H33: Indoor to outdoor rated voltage is different.

F11: 4-way valve switching abnormality.

F17: Indoor standby units freezing abnormality. Check for expansion valve leakage or sensor issues.

F91: Refrigeration cycle abnormality. Often caused by insufficient refrigerant or a closed valve.

F93: Compressor abnormal revolution. Could be a faulty power transistor module or compressor lock.

F96: Power transistor module overheating protection.

F97: Compressor overheating protection.

F98: Total running current protection.

The PANASONIC CU-4E23JBE includes several protection controls to prevent compressor damage:

Gas Leak Detection Control 1: If the compressor operates for 5 minutes with low total current and specific temperature conditions (e.g., indoor intake below 4 degrees Celsius in cooling), the compressor stops and restarts after 3 minutes. If this occurs 4 times within 60 minutes, the unit stops and displays error F91.

Gas Leak Detection Control 2: If the compressor is OFF due to this control, error F91 is memorized in the EEPROM. If it happens twice within 60 minutes, the indoor unit Timer LED will blink.

Valve Close Detection: In the first 5 minutes of cooling after installation or pump down, if the temperature difference suggests a closed valve, the compressor stops and the Timer LED blinks.

Discharge High Pressure Protection: A high pressure switch activates to stop the compressor during cooling or heating if pressure exceeds safe limits. If this occurs 4 times within 30 minutes, error F94 is indicated.

Time Delay Safety Control: The compressor will not restart for three minutes after it has been stopped to ensure pressure stabilization.