Panasonic CS-MKS9NB4U Technical & Service Manual page 34

(3) Serial Communication Error Identification Procedure
If the lamps on the main body show the following conditions after the completion of self-diagnostics,
a communication error between the indoor unit and outdoor unit might be considered.
In such a case, identify the breakdown section by using the following procedure.
Refer to "Method of Self-Diagnostics" for the self-diagnostics procedure.
NOTE
Lamp Operation
Condition
E01
E12
< Before the Operation >
For terminal strip short circuit work or inter-unit wiring removal, turn off the power
Warning
to avoid an electric shock.
Release the terminal strip short circuit after the completion of self-diagnostics.
Do not perform the short-circuit work between any other terminals except for
Caution
specified ones on the specified terminal strip. If such work is performed between
the incorrect terminals, the unit might be broken.
< Convenient Tool for Short-Circuit Work ( for example ) >
< Check Items before Troubleshooting Serial Communication Start >
After confirming that the following errors do not exist, start the "Troubleshooting Serial Communication"
in "Condition: E01 and E12".
1. Mis -wiring (inter-unit cable, etc.)
2. AC power failure
3. Blown fuse
4. Power Relay failure
5. Outdoor Fan Motor failure (defective insulation, etc.)
(3-1) Condition: E01
Troubleshooting Serial Communication
Is the voltage of about DC12V
or more given between the terminals
2 and 3 on the outdoor unit terminal strip
(Serial Communication Line) ?
(Fig. 1)
( Continued to the next page A. )
Timer High Power
Yes
A
: Off
: Blinking
: Illuminated
Alligator Clip
6. Reactor failure (defective insulation, etc.)
7. High-Pressure Switch failure
8. Overload Relay failure
9. Magnetic Coil failure (defective insulation, short-circuit, etc.)
10. Compressor failure (defective insulation, etc.)
- +
V
Outdoor Unit
1 2 3 4 5
Power
1 2 3
Indoor Unit
Fig. 1
1. Turn OFF the power and wait until the power lamp (LED)
No
of the outdoor unit controller is turned OFF.
2. Disconnect the cable from the terminal 3 on the indoor unit
terminal strip.
3. Turn ON the power.
( Continued to the next page B. )
34
Cable
Alligator Clip
Outdoor Unit
1 2 3 4
6
1 2 3
Indoor Unit
V
+
-
Fig. 2
(Fig. 2)
B
Prohibit
5 6
Power