Friedrich FPHMR18A3A Service Manual page 83

Outdoor Fault Codes
Fault code Fault description
7 The communication fault
between the indoor unit
and outdoor unit
13 Compressor overheat
protector device
14 The high pressure switch
operation or the unit
is turned off for high
pressure protection
15 the low pressure
switch protection or
the unit turn off for low
pressure protection
16 Overload protection in
cooling mode
83
TROUBLESHOOTING
Possible reasons for
abnormality
"1. The connection cable is
connected improperly between
the indoor unit and outdoor
unit;
2. The communication cable is
connected loosely;
3. The communication cable
fails;
4. The indoor control board
fails;
5. The outdoor control board
fails;
6. Communication circuit fuse
open;
7. The specification of
communication cable is
incorrect."
"1. The wiring of the overload
protector is connected loosely.
2. The overload protector
fails .
3. The refrigerant is not
enough;
4. The installation pipe is
much longer than the normal
one, but extra refrigerant is
not added ;
5. The expansion valve fails;
6. The outdoor control board
fails."
"1. The wiring of the high
pressure protector is
connected loosely;
2. The high pressure protector
fails
3. The outdoor control board is
abnormal;
4. Overload in cooling;
5. Overload in heating."
1. The wiring of the low
pressure
switch connect loose;
2. The low pressure switch is
failure;
3.The refrigerant is not
enough;
4.The expansion valve failure
in
heating mode;
5.The outdoor control board is
abnormal.
System overload
How to deal with
"1. Reconnect the connection
cable referring to the wiring
diagram;
2. Reconnect the
communication cable;
3. Replace the
communication cable;
4. Replace the indoor
control board;
5. Replace the outdoor
control board;
6. Check the communication
circuit, adjust the DIP switch
and the short‑circuit fuse.
7. Choose suitable
communication cable
referring to the user
manual"
"1. Reconnect the wiring of
the overload protector;
2. Replace the overload
protector;
3. Check the welding point
of the unit to confirm
whether it is leakage,
and then recharge the
refrigerant;
4. Add the refrigerant;
5. Replace expansion valve;
6. Replace the outdoor
control board."
"1. Reconnect the wiring of
the high pressure protector;
2. Replace the high pressure
protector;
3. Replace the outdoor
control board;
4. Please refer to the Note 3;
5. Please refer to the Note
4."
1. Reconnect the wiring of
the
low pressure switch;
2. Replace the low pressure
switch;
3.Check the welding point to
confirm whether the unit is
leakage, and then
add some refrigerant;
4. Replace the expansion
valve;
5. Replace the outdoor
control
board.
Please refer to the Note 3.
Remarks
Applied to models with
high pressure switch or
pressure sensor
Applied to
models with
low pressure
switch or
pressure
sensor