Daikin ARXN25MV1B, Service Manual

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Appendix A
62
6.5 Inverter analyzer check
If an abnormal stop occurs due to compressor start up failure or over current output when using an
Inverter unit, it is dif
fi cult to judge whether the stop is caused by compressor failure or some other failure
(main PCB, power module and etc.). The inverter analyzer makes it possible to judge the cause of trouble
easily and securely. (Connect an inverter analyzer as quasi-compressor instead of compressor and check
the output of the inverter)
Operation Guide
a. Turn off the power
b. Install Inverter analyzer instead of compressor
c. Press cooling operation ON/OFF button for 5 seconds
Compressor
(1) Remove the terminals from
the compressor.
(2) Connect the terminals to the
terminals of the inverter analyzer.
Be careful not to let the terminals (U,
V, W) touch each other. Otherwise,
high voltage is applied.
Install an inverter analyzer instead of a compressor.
Inverter analyzer
Diagnosis Guide (according to 6 LEDs lighting status)
a. If all LEDs are lit uniformly, compressor is defective and need to replace.
b. If the LEDs are not lit uniformly, check the power module as below.
i. Disconnect compressor harness connector from outdoor PCB.
ii. Follow table below to measure resistance between (+) or (-) power module terminal or diode bridge
and the U, V, or W terminal of compressor with a multimeter. Evaluate the measurement results
referring to following table.
Negative (-) terminal of
multimeter Power module (+)
or Diode bridge (+)
UVW
Power module (-)
or Diode bridge (-)
UVW
Positive (+) terminal of
multimeter
UVW
Power module (+)
or Diode bridge (+)
UVW
Power module (-)
or Diode bridge (-)
Resistance is OK Several k Ω ~ several M Ω
Resistance is NG 0 Ω or ∞
*Remark:
1. Make sure voltage between (+) and (-) of power module or the diode bridge is approximately 0V before checking
2. Use opposite sign of terminal for digital multimeter for measurement.
c. If NG in power module check, replace the main PCB.
d. If OK in power module check, observe any solder cracking on PCB.If there is any solder cracking
found, replace PCB or repair the soldered section. If there is no solder cracking, replace PCB.
Caution
a. When the output frequency is low, the LEDs blink slowly. As the output frequency increases, the
LEDs blink quicker. (The LEDs look like they are lit)
b. Upon completion of the inverter analyzer diagnosis, be sure to re-crimp the FASTON terminals.
Otherwise, terminals may be burned due to loosening.