Daikin R-410A Service Manual page 171

ESIEN05-04
Troubleshooting
Caution Be sure to turn off power switch before connect or disconnect connector, or parts damage may be
occurred.
Part 3 – Troubleshooting
· Indoor unit fan runs at set airflow rate.
· (In cooling operation)
When air thermistor ambient temperature is higher than set temperature
· (In heating operation)
When air thermistor ambient temperature is lower than set temperature
Is the power
switch OFF or the fuse for
power switch
blown?
NO
Is the heating
switch turned on at outdoor
temperature >30˚C
NO
Is rated voltage
applied at
the compressor
terminals?
NO
Is rated voltage
output from the magnetic
switch or power
transistor?
NO
Is rated voltage output
from the PC board?
NO
Air sensor
Indoor unit
PC board
Input Output
to PC from
board PC
board
YES
YES
YES
YES
YES
Outdoor unit
Magnetic
PC board
switch
Relay
Output from
Input
Output from
magnetic
to PC
relay or
switch or SW
board
microcomputer
circuit of
transistor
Troubleshooting
Turn on the power
switch or replace fuse.
Normal.
(Thermostat OFF by
outdoor temperature)
Replace the
compressor.
Replace the magnetic
switch or power
transistor.
Replace the PC board.
Check the thermistor.
COMP
Output from
magnetic
switch or
U,V,W of
power power
transistor
(S2576)
1
3 3
4
5
3–9