Regulations on wire size differ from locality to locality. For field wiring requirements, please refer to your local electri- cal codes. Make sure that the installation fully complies with all local and national regulations.

(1)Remove access panel “C”. (Fig. 32)

(2)Connect the inter-unit and power supply line accord- ing to the drawing on the panel side.

(3)Be sure to size each wire allowing approx. 4"

(10 cm) longer than the required length for wiring. Store excess wiring inside the cabinet.

(4)When connections are completed, check that all con- nections are correct as shown in the wiring system diagram on panel side.

(5)Be sure to ground the unit according to your local codes.

6. Test Run

Performing a test run

Refer to the test run procedures in the indoor unit installation manual.

Perform the test run separately for each connected indoor unit. If 2 units are operated simultaneously, it is not possible to correctly check for errors in tubing and wiring.

If the room temperature is 59°F (15°C) or below, it may not be possible to check for tubing errors with cooling operation. If this occurs, perform heating operation for each unit individually, and check that warm air is discharged from each unit. If there is cold air mixed in with the warm air, check the tubing connections again.

Checking tubing and wiring

Perform the test run and check that operation is normal. If there is an error in tubing or wiring, the refrigerant may flow to indoor unit B when indoor unit A is operated (for example).

CAUTION

Stop operation immediately if there is an error in tubing or wiring. Turn the power (breaker) to OFF, and check whether the inter-unit cables are connected incorrectly, or whether the narrow tubes A and B are connected in reverse. Correct the connections.

If there is an error in tubing, pump-down must be per- formed. Be sure to perform pump-down. After making corrections, again purge the air from the tubes.

Lock nut

Cabinet

 

Terminal block

Conduit plate

Plug

Access panel “C”

Inter unit

Power supply

(Conduit)

(Conduit)

Fig. 32

Access panel C

Conduit plate

CAUTION

Make sure there is no gap between access panel “C” and the conduit plate.

Fig. 33

26

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Panasonic CU-3KE19NBU, CU-4KE31NBU, CU-4KE24NBU service manual Test Run, Performing a test run, Checking tubing and wiring

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.

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