Daikin FTX25JVEA9 Service Manual page 316

Si18-201
3.4.6 Power Transistor Check (Capacitor Voltage
Check No.6 Power Transistor Check
"
"
"
"
∗
Capacitor Voltage Check
"
Negative (–) terminal of tester
(positive (+) terminal for digital
type)
Positive (+ terminal of tester
(negative (–) terminal for digital
type)
Normal resistance
Resistance for NG
Service Diagnosis
Do not touch the charging unit for 10 minutes after turning the breaker off.
Even when touching the charging unit after 10 minutes, use a multiple meter to ensure that
the power supply voltage of power transistor is 50V or less.
Measure U,V,W either on terminals of control PC board on the substrate side or on the
compressor terminals.
Measure (+),(–) of the power transistor on (+) / (–) section of capacitor as shown in the figure
below.
If the resistance value is not normal, replace the control PC board.
Follow the below figure to measure the capacitor voltage with breaker kept ON, while take
enough care not to touch the charging unit .
Troubleshooting - Outdoor Unit Related
Check)
(+) of power UVW
transistor
UVW (+) of power
transistor
∞
Several KΩ to
several MΩ
0 to several Ω
0
(–) of power UVW
transistor
UVW (–) of power
transistor
∞
Several KΩ to
several MΩ
0 to several Ω
0
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