Mitsubishi Electric MXZ-8B48NA, Technical & Service Manual, Page: 62 / 88

62
Forced defrost Start Normal
Normal
—
When compressor is
working in heating
operation.
+
Abnormal history clear
No function
Self-diagnosis
(Indoor unit selection)
Indicating a particular
self-diagnosis
Clear
—
off or operating
—
Test run Operating OFF
Under suspension
Test run mode setting Heating Cooling
Indoor No.1
Indoor No.4
Indoor No.7
Indoor No.2
Indoor No.5
Indoor No.8
Indoor No.3
Indoor No.6
1
2
3
4
5
6
1
2
ON OFF
No.
Function Effective timing
Action by the switch operation
Switch
SW1
Dip
switch
SW4
Type of
Switch
OC
<Example>
A B C D E A B C
IC
RC
IC IC
RC
Indoor
No.1
Indoor
No.2
Indoor
No.3
Indoor
No.4
Indoor
No.5
R
C
IC
R
C
IC
R
C
BC#1 (5- branch type)
BC#2 (3- branch type)
BC#1 : branch box controller unit Number 1
1 blinking LED2 (branch box controller board)
BC#2 : branch box controller unit Number 2
2 blinking LED2 (branch box controller board)
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
1
ON
2 3 4 5 6
9-8. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS
(1) Function of switches
MXZ-8B48NA MXZ-8B48NAR1
The black square (
Ŷ
) indicates a switch position.
Forced defrost should be done as follows.
1
Change the DIP SW1-1 on the outdoor controller board from OFF to ON.
2
Forced defrost will start by the above operation
1
if these conditions written below are satisfied.
• Heat mode setting
• 10 minutes have passed since compressor started operating or previous forced defrost finished.
• Pipe temperature is less than or equal to 8
:
[46 °F].
3
Forced defrost will finish if certain conditions are satisfied.
w
Forced defrost can be done if above conditions are satisfied when DIP SW1-1 is changed from OFF to ON.
After DIP SW1-1 is changed from OFF to ON, there is no problem if DIP SW1-1 is left ON or changed to OFF again. This
depends on the service conditions.