Daikin R407C PLUS - Failure Diagnosis for Inverter System; Points of Diagnosis

Si33-105 Failure Diagnosis for Inverter System
Troubleshooting R407C PLUS Series Heat Recovery System 193
4. Failure Diagnosis for Inverter System
4.1 Points of Diagnosis
The main causes for each malfunction code are given in the table below. (For details refer to the
next page and those following.)
"
: Failure is probable
#
: Failure is possible
(
: Failure is improbable
— : Failure is impossible
Malfunction
code
Contents of
malfunction
Location of failure
Point of
diagnosis
Inverter
Compressor Refrigerant
system
Outdoor
unit PC
board
Other
Field
cause
PC board
power
unit
Other
L4 Radiator fin
temperature
rise
("
————
(
Is the intake port
of the radiator fin
clogged?
L5 Instantaneo
us over-
current
#
—
"(
———
Inspect the
compressor.
L8 Electronic
thermostat
(
—
"#
———
Inspection the
compressor and
refrigerant
system.
L9 Stall
prevention
(
—
#"
———
Inspection the
compressor and
refrigerant
system.
LC Malfunction
of
transmission
between
inverter PC
board and
outdoor unit
PC board
#"
——
(
——
Inspect the
connection
between the
inverter PC
board and
outdoor unit PC
board. Next,
inspect the
inverter PC
board.
U2 Abnormal
current/
voltage
##
———
("
•
Inspect the fuse
on the inverter
PC board.
•
Check the DC
voltage.
P1 Over-ripple
protection
##
————
#
•
Open phase
•
Current/voltage
imbalance
•
Defect of main
circuit wiring
P4 Defect of
radiator fin
temperature
sensor
#(
—————
Inspect the
radiator fin
thermistor.