Panasonic Cs Kexxnb4x Cz 18bt1u Service Manual

NOTE
7-3-3. Remove the ceiling panel.
(1)  Open the clamp (4 locations) and remove the 2 lead wires from the clamps. (Fig. 6)
(2)  Remove the 4 screws fixing the corner cover (at 3 locations) and indicator cover (at 1 location). (Fig. 6)
(3)  Press the center 1 of the cover and remove the cover with the section 2 pulled down. (Fig. 7)
(4)  Remove the strap (3 locations) from the hook on the ceiling panel. (Fig. 8)
There is no strap on the indicator cover.
(5)  Remove the bolt (4 locations) with a washer...

123
7-3-4.  Remove the indoor air temperature sensor.
(1)  Disconnect the connector CN08 (ROOM 2P) in the control box and remove the indoor air temperature 
sensor. (Fig. 10)
7-3-5. Remove the power box and control box.
(1)  Remove a screw and remove the terminal cover. (Fig. 11)
(2)  Remove the 2 screws and remove the power box cover. (Fig. 11)
(3)  Disconnect the power lines (No. 1 and No. 2) / signal line (No. 3) and ground cable from the terminals in 
the power box. (Fig. 12)
Indoor air temperature...

12 3
(4)  Disconnect the connector CN07 (DP 2P) in the power box. (Fig. 13)
  Remove a screw and disconnect the ground cable. (Fig. 13)
(5)  Disconnect the connector CN03 (DCM 6P) in the power box. (Fig. 14)
(6)  Remove the 4 screws and remove the power box. (Fig. 14)
(7)  Disconnect the connectors CN06 (FS 3P) and CN09 (COIL-1 2P) in the control box. (Fig. 15)
(8)  Remove the 2 screws and remove the control box. (Fig. 15)
Fig.13
Fig.14
Fig.15
Screw
Screw
Screw
Screw
Screw
CN06 CN03ScrewScrew Ground...

For the removal of the following components, perform any work after removing the indoor 
unit (main body) from the ceiling.
    Main body lower section      Heat exchanger sensor      Drain pump
    Float switch      Turbo fan      Fan motor
    Heat exchanger 
1.  Perform the work after draining the water to prevent the water leakage from the drain pan.
 
• Put a bucket, etc., under the drain cap and remove the drain cap to drain the water. 
    (Fig. 16)
2.  Refer to the installation instructions for...

7-3-7. Remove the heat exchanger sensor.
(1)  Remove the heat exchanger sensor from the sensor holder. (Fig. 19) 
7-3-8. Remove the drain pump and float switch.
(1)  Remove the 2 screws (Fig. 20)
(2)  Loosen the clamp and disconnect the drain hose from the drain pump. (Fig. 20)
(3)  Remove the drain pump from the main body upper section. (Fig. 20)
(4)  Remove a nut and remove the float switch. (Fig. 21)
Heat exchanger sensor
Fig.20 Fig.21Fig.19
Holder
Drain pumpScrew
ClampFloat switch
Nut
Drain hose
45 

7-3-9. Remove the turbo fan and fan motor.
(1)  Remove a nut and remove the turbo fan. (Fig. 22)
(2)  Remove the 2 screws and 3 nuts, and remove the fan motor. (Fig. 23) 
7-3-10. Remove the heat exchanger.
(1)  Remove the 3 screws. (Fig. 24)
(2)  Remove the 3 screws. (Fig. 25)
(3)  Remove the heat exchanger from the main body upper section with the heat exchanger lifted.Fig.22 Fig.23
Fig.24 Fig.25
Turbo fan
NutScrew Nut
Fan motor
Screw
Screw Heat exchanger
Screw Main body 
upper section
46 

Emergency operation SENSOR DRY
AUTO cooling/heating operation
  Selecting the operation mode  During DRY operation, the system adjusts the room 
temperature and fan speed according to the conditions in the 
room, in order to maintain a comfortable room environment.
SENSOR DRY operation
  •  DRY operation is as shown in the figure below.
PAM-    control
•  In order to further improve inverter performance, control is 
switched between PWM control at low operation speeds, and 
PAM control at high operation...

HIGH POWERNIGHT SETBACK
Lamp colors
Timer backup
This function acts to raise the power but keeps the AC system in 
the same operating mode.
This function is set with the HIGH POWER button on the remote 
controller.
(It can be set regardless of the temperature and fan speed 
settings.)
 HIGH POWER operation from remote controller
  The unit operates at maximum output for 30 minutes, 
regardless of the desired temperature.
  The fan speed is 1 step above "High."
OPERATION lamp  When HIGH POWER...

Overload prevention during heating
During HEAT operation, the temperature of the indoor heat 
exchanger is used to control the frequency and lessen the load 
on the compressor before the protective device is activated.
Cold-air prevention during heating
Compressor discharge temperature control
During heating, the fan speed is set to "LL" (very low) or stopped.
As the temperature of the indoor heat exchanger rises, the fan 
speed is changed to the set speed.
Freeze prevention
During COOL or DRY...

This function prevents the circuit breaker or fuse from operating
 to open the circuit. This function works when electrical current 
has increased due to an increase in the cooling / heating load, 
or to a decrease in the power supply voltage. In these cases, 
operation frequency is reduced or operation is interrupted auto-
matically to control the electrical current for operation.
When the cause of the increase in electrical current is rectified, 
the system will resume operation in the original mode....