– 91 –
11. How to Diagnose the Trouble
The pulse modulating circuits are mounted to both indoor and outdoor units.
Therefore, diagnose troubles according to the trouble diagnosis procedure as described below.
(Refer to the check points in servicing written on the wiring diagrams attached to the indoor / outdoor units.)
Table 11-1
NOTE
A large-capacity electrolytic capacitor is used in the
outdoor unit controller (inverter). Therefore, if the
power supply is turned off, charge (charging voltage
DC280 V to 373 V) remains and discharging takes a
lot of time (for more than 5 minutes). After turning off
the power source, if touching the charging section
before discharging, an electrical shock may be
caused.
Discharge the electrolytic capacitor completely by
using solder iron, etc.
WARNING
The electrolytic capacitor may not normally discharge
according to error contents and the voltage may
remain.
Therefore, be sure to discharge the capacitor.
WARNING
For discharging, never use a screwdriver and others
for short-circuiting b and – electrodes, As the
electrolytic capacitor is one with a large capacity, it is
very dangerous because a large electric spark will
occur.
<Discharging method>
Connect the discharge resistance (approx. 100
Ω
/ 40
W) or plug of the soldering iron to voltage b
and – of C13 on the main P.C. board MCC-1571, and
then perform discharging.
Fig. 11-1
No.
Troubleshooting Procedure
Page
1
First Confirmation
92
2
Primary Judgment
93
3
Judgment by Flashing LED of Indoor Unit
93
4
Self-Diagnosis by Remote Controller
(Check Code)
94
5
Judgment of Trouble by Symptom
97
6
Trouble Diagnosis by Outdoor LED
103
7
Troubleshooting
110
8
Inspection of the Main Parts
111
9
How to Simply Judge Whether Outdoor
Fan Motor is Good or Bad
115
Discharge po and - of C13
(Discharging period: 10 seconds or more)