Service Functions - Mitsubishi Electric MFZ-KA25VA Service Manual

9

SERVICE FUNCTIONS

MFZ-KA25VA
MFZ-KA35VA
MFZ-KA50VA
9-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board.
The time will be shortened as follows. (Refer to 10-7.)
Set time : 1-minute
Set time : 3-minute
9-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, both the P.C. boards of remote controller
and the electronic control P.C. boards must be modified according to the number of the indoor unit.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
Remote controller model : KM05G
The P.C. board has the print "J1" and "J2". Solder "J1" and "J2" according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.
Table 1
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
How to modify the electronic control P.C. board
Turn OFF the power supply before modification. Cut off "JR05" and "JR06" on the electronic control P.C. board according
to the number of indoor unit as shown in Table 2. (Refer to 10-7.)
Table 2
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
NOTE : After modification, turn ON the power supply and with the remote controller headed towards the indoor unit, press the
OPERATE/STOP(ON/OFF) button. If one or two beeps is heard from the indoor unit, modification is completed
correctly.
1-second
3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is
shortened by short circuit of JPG and JPS.)
J1
1 unit operation
No modification
–
–
–
JR05
No modification
Cut off JR05
No modification
Cut off JR05
J2
2 units operation
Same as at left
Solder J1
–
–
JR06
VARISTOR (NR11)
No modification
No modification
Cut off JR06
Cut off JR06
19
NOTE : For remodelling, take out the bat-
teries and push the
OPERATE/STOP(ON/OFF) button
twice or 3 times at first.
After finish remodelling, put back
the batteries then press the
RESET button.
3 units operation
Same as at left
Same as at left
Solder J2
– Solder both J1 and J2
Indoor electronic
control P.C. Board
Fuse (F11)
JR05
IC101
CN1X1 CN1Y1
T11
R111
C111
4 units operation
Same as at left
Same as at left
Same as at left
JR06
CN151
CN152
CN211
CN212