FILE NO. SVM-05026
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B
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10-7. How to Diagnose Trouble in Outdoor Unit
10-7-1. Summarized inner diagnosis of inverter assembly
Diagnosis/Process flowchart
Item
Preparation
Check
Operation
Measurement
Check
Stop
Check
Measurement
Summary
If fuse was blown,
be sure to check the
electrolytic capacitor
and diode block. (DB01)
•
Connect discharge
resistance (approx.
100
Ω
40W) or soldering
iron (plug) b, –
terminals of the electro-
lytic capacitor (760
µ
F)
of C12 (with printed
CAUTION HIGH VOLT-
AGE) on P.C. board.
If 15A fuse is blown,
discharge both edges
of the electrolytic
capacitor with
soldering iron.
OK if 760
µ
F
→
DC280 to 320V
Remove CN300 by
pushing the part
(an arrow indication)
because CN01 is a
connector with lock.
→
Resistance between
phases should be
approx. 55 to 77
Ω
→
Should be 10M
Ω
or
more
Contents
Turn “OFF” the power
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 power breaker,
and operate the air
conditioner in COOL
mode by short-circuit of
the timer.
Measure terminal voltage
of the electrolytic capacity.
760mF: 400WV x 3
After operation, turn off
the power breaker after 2
minutes 20 seconds
passed, and discharge
the electrolytic capacity
by soldering iron. Check
voltage between motor
phases.
•
Is not winding
between
1
-
2
,
2
-
3
,
or
1
-
3
opened or
short-circuited?
•
Is not frame grounded
with
1
,
2
or
3
?
Remove
connector of
compressor.
Check 15A fuse
(Part No.F01).
OK
Replace fuse.
Check
electrolytic
capacitor, diode
block (DB01),
etc.
Check
terminal voltage
of electrolytic
capacitor.
NG
Check
electrolytic
capacitor, diode
(DB01), etc.
Does outdoor
fan rotate?
Does LED on control
board flash or go on?
Remove connector
CN300 of outdoor fan
motor, and using a
tester, check
resistance value
between every phase
at motor side
Replace
outdoor
fan motor.
YES
NG
NO
NO
OK
NG
OK
YES
Discharging position
(Discharging period
10 seconds or more)
Plug of
soldering
iron
