Friedrich MD24Y3J Svc Manual page 54

Display
Title
code
05
Communication
/
(Indoor÷Outdoor)
53
Check Flow Chart
Check the input power
AC230V (Outdoor,
Indoor unit)
Is it normal ?
(230V±10%)
Yes
Check the communication
wires are correctly
connected.
Is it normal ?
Yes
Check the resistance
between communication
line and GND.
(Normal : Over 2M)
Is it normal ?
Yes
Is connector for
communication
correctly connected?
Only for training and service purposes
Cause of error
• The connector for trans-
mission is disconnected.
• The connecting wires
are misconnected.
• The communication line
is break
• Outdoor PCB is
abnormal.
• Indoor PCB is abnormal.
• Synchro # of IDU is
abnormal.
No
Needs electric work
No
Adjust the connection
of wire Confirm the
wire of "Live",
"Neutral", "Signal"
No
Correct connection
- 54 -
Check point & Normal condition
• Check power input AC 230V. (Outdoor, Indoor)
• Check connector for transmission
• Check wires are misconnecting.
• Check transmission circuit of outdoor PCB
• Check transmission circuit of indoor PCB
• Check # of IDU setting DIP SW
Is the connection of
GND,GND1,GND2,
correctly connected?
Yes
Change PCB
1(L1) 2(L2) 1(L1) 2(L2)
❊ CH05 is displayed at indoor unit,
CH53 is displayed at outdoor unit.
No
Correct connection