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FILE NO. SVM-03008
10-7. How to Diagnose Trouble in Outdoor Unit10-7-1. Summarized inner diagnosis of inverter assembly
Diagnosis/Process flowchart Item Contents Summary
Preparation
Check
Check
Operation
Measurement
Check
Stop
Check
Measurement
If fuse was blown,
be sure to check the
electrolytic capacitor
and diode block. (DB01)
•Connect discharge
resistance (approx.
100Ω40W) or soldering
iron (plug) between +, –
terminals of the electrolytic
capacitor (500µF)
of C14 (with printed
CAUTION HIGH VOLT-
AGE) on P.C. board.
OK if 500µF →
DC280 to 380 V
Remove CN300 by pushing
the part an arrow because
CN01 is a connector with
lock.
→Resistance between
phases should be approx.
55 to 77Ω.
→Should be 10MΩ or
more.
Turn “OFF” the power
breaker, and remove 3P
connector which connects
inverter and compressor.
•Check whether 25 A 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
electrolytic capacity.
500µF: 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?
Discharging position
(Discharging period
10 seconds or more)
Plug of
soldering
iron
A B C
NG
NG
NO
NG
NO
OK
OK
OK
YES
YES
Remove
connector of
compressor.
Check 15 A fuse
(Part No.F01).
Replace fuse.
Check
electrolytic
capacitor,
diode block
(DB01), etc.
Check
terminal voltage
of electrolytic
capacitor.
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.