Service manual

SERVICE FUNCTIONS
86
11
11-1. COMPULSORY DEFROSTING MODE FOR SERVICE <MUH-A07/A09/A12WV>
By short circuit of the connector JPDS and JPSG on the outdoor deicer P.C. board, defrosting mode can be accom-
plished regardless of the defrost interval restriction. (Refer to page 103.)
Defrost thermistor RT61 must read below -3°C.
11-2. CHANGE IN DEFROST SETTING <MUH-A07/A09/A12WV>
<JRF> When the JRF wire of the deicer P.C. board is cut, the defrost interval time will be changed. (Refer to page 103.)
<JRG> When the JRG wire of the deicer P.C. board is cut, the defrost temperature will be changed. (Refer to page 103.)
MUH-A07WV -
MUH-A09WV -
MUH-A12WV -
Jumper wire
JRF
JRG
MODEL Change point
Defrost interval time changes from 40 minutes to 15 minutes
Deforst start temperature changes from -3: to 0:
Deforst finish temperature changes from 3.1: to 10.1:.
E1
E1
E1
11-4. 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, P.C. boards of remote controller must be
modified according to the number of the indoor unit.
11-3. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS the electronic control P.C. board.
The time will be shortened as follows. (Refer to page 102.)
Set time : 1 minute ➔ 1-second
Set time : 3 minutes ➔ 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.)
How to modify the remote controller P.C. board
Remove batteries before modification. The board has a print as shown below :
NOTE : For remodelling, take out the bat-
teries and press the
OPERATE/STOP(ON/OFF) button
twice or 3 times at first.
After finish remodelling, put back
the batteries then press the
RESET button.
The P.C. board has the print “J1” and “J2”.
Solder “J1” and “J2” according to the num-
ber of indoor unit as shown in Table 1.
After modification, press the RESET button.
No. 1 unit
No. 2 unit
No. 3 unit
No. 4 unit
1 unit operation
No modification
–
–
–
2 units operation
Same as at left
Solder J1
–
–
3 units operation
Same as at left
Same as at left
Solder J2
–
4 units operation
Same as at left
Same as at left
Same as at left
Solder both J1 and J2
MSC-A07WV - MU-A07WV - MUH-A07WV - MUX-A10WV - MUX-A25WV -
MSC-A09WV - MU-A09WV - MUH-A09WV - MUX-A19WV - MUX-A26WV -
MSC-A12WV - MU-A12WV - MUH-A12WV - MUX-A20WV -
E1E1E1E1
E1E1E1E1E1
E1E1E1E1E1
Table 1
OB307C-3.qxp 04.5.11 1:18 PM Page 86