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(2) Outdoor unit transmission power source circuit failure judgment
Check and modify transmission line for
disconnection & poor contact
Check and modify indoor/outdoor
transmission line for short circuit.
Check wiring between connectors (CNS1 and TB3).
Check pulling off of connector (CNS1).
Replace main board.
Modify pulling off of connector.
Replace INV board.
Modify pulling off of connector.
Modify wiring.
Replace fuse.
Apply power source again.
Replace diode stack.
Replace rush current protection resistor.
Check and modify wiring between main board
connector (CNVCC1) and INV board connector
(CNVCC1).
Check and modify shorting of trans-
mission line for centralized control.
Modify pulling off of connector.
Confirm and modify power source
wiring and main power source.
Check voltage of indoor/outdoor transmis-
sion terminal block (TB3) of outdoor unit.
DC24 ~ 30V
DC24 ~ 30V
Check voltage between 1 and 2, and 1 and 3
of main board CNVCC1
Check voltage of outdoor unit power
source terminal block TB1.
Check fuse (F02) on INV board.
Broken?
YES
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
NO
YES
NO
NO
NO
NO
YES
NO
INV board :
G/A board :
CNDC2
CNDC1
Check wiring inside outdoor unit.
G/A board : CNDC1 INV board : CND2
–
42 ~ 52
Ω
Check voltage of TB3 by removing
transmission line from TB3.
Replaced
Check whether power supply connector is
replaced with CN40.
DC24 ~ 30V
Connector being
pulled off?
Connector being
pulled off?
Check voltage of terminal block for
centralized control (TB7).
DC24 ~ 30V
Check voltage of TB7 by removing
transmission line from TB7.
DC24 ~ 30V
Check voltage between 1 and 2, and 1 and 3
of main board CNVCC1
DC24 ~ 30V
Check connector (CNL1 and CNL2) on filter
board for pulling off.
Connector being pulled off?
Check voltage between 1 and 3 of INV
board CNDC2.
DC517 ~ 587V
AC342 ~ 457V
Faulty wiring?
Damaged?
Check rush current protection resistance.
Check diode stack.
Check connector on outdoor unit board for pulling off.
Connector being pulled off?
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
YES
YES
YES
YES