Daikin VRV RXYQ72-384XAYCA, Руководство по обслуживанию

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SiUS342004EB Troubleshooting by Error Code
Part 6 Service Diagnosis 326
3.60 Power Supply Insufficient or Instantaneous Abnormality
Applicable
Models
All outdoor unit models
Error Code
U2
Method of Error
Detection
Detect the voltage of capacitor of the main circuit in the inverter PCB.
Error Decision
Conditions
When the voltage in the DC circuit (between diode module and power module) falls below 560
VDC.
Supposed
Causes

Abnormal power supply voltage

Instantaneous power failure

Open phase

Defective inverter PCB

Defective outdoor unit main PCB

Defective compressor

Defective main circuit wiring

Defective fan motor

Defective connection of signal cable
Troubleshooting
There are
some defects in the
power s u pply conditions
aforementioned.
The ins u lation
resistance of the
compressor is less than
100 k .
NO
YES
YES
Fix the defects.
Replace the compressor
(M1C).
Check for power s u pply
conditions.
(1) Power s
u pply v oltage falls
within ±10 % of the rated
v oltage?
(2) Any open phase in the
power s u pply wiring or any
wrong wiring?
(3) Im b alance in the power
s u pply v oltage is
maintained within 12 V?
A
NO
Caution
Be s u re to t u rn off the power switch b efore connecting or disconnecting
connectors, or parts may b e damaged.
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