Diagnosis/Process flowchart Item
Preparation
Check
Operation
Measure-
ment
Stop
Check
Measure-
ment
Contents
Tu r n “OFF” the power supply
breaker, and remove 3P
connector which connects
inverter and compressor.
• Check whether 25A fuse
on the control board
assembly is blown or not.
(F01)
Turn on the power breaker,
and operate the air condi-
tioner in COOL mode by time
shortening.
Measure terminal voltage of
the electrolytic capacity.
After operation, turn off the
power breaker after 2 minutes
20 seconds passed, and
dischar
ge the electro-lytic
capacitor by soldering iron.
Check voltage between
motor
phases.
Summary
If fuse was blown, be sure to
check the electrolytic
capacitor and diode block.
(DB01)
• Connect discharge
resistance (approx. 100Ω,
40W) or soldering iron
(plug) between +, –
terminals of the electro-
lytic capacitor (760µF) of
C09, C10 (with printed
WARNING ELECTRIC
SHOCK) on P.C. board.
OK
if 760µF → DC280 to 380V
Remove CN300 while
pushing the part indicated
by an arrow because
CN300 is a connector with
lock.
→ Resistance between phases
should be approx
33.7 ± 1.7Ω (RAS-18k,22k)
18.8Ω (RAS-24k)
→ Should be 100MΩ or more.
Replace
outdoor
fan motor.
Remove connector
of compressor.
NG
NG
NG
NO
OK
OK
OK
YES
Check 25A fuse
(Part No.F01).
Does outdoor
fan rotate?
Replace fuse.
Check
electrolytic
capacitor, diode
block (DB01),
etc.
Check
electrolytic
capacitor, diode
(DB01),
etc.
Remove connector
CN31 of outdoor fan
motor, and using a
tester, check resistance
value between every
phases at motor side.
Check
terminal voltage
of electrolytic
capacitor.
BA
760
µ
F:400V x 2
Table 11-7-1
Is winding between 1 - 2 ,
2 - 3 or 1 - 3 opened or
short-circuit ?
Is frame grounded with
1 , 2 or 3 ?
11-7. How to Diagnose Trouble in Outdoor Unit
11-7-1. Summarized Inner Diagnosis of Inverter Assembly