Hitachi RAC-18WPA Manual Do Utilizador
14-14
14.4 CHECKING THE INDOOR UNIT ELECTRICAL PARTS
14.4.1 NO POWER IS DETECTED (NO OPERATION)
14.4.1.1 MONO SPLIT
No
No
Check the power cable,
power switch, and terminal
board, and repair any
defective part
power switch, and terminal
board, and repair any
defective part
Check the indoor/outdoor
unit connection cable, and
conduct any defective
section (wrong
connection, incomplete
insertion)
unit connection cable, and
conduct any defective
section (wrong
connection, incomplete
insertion)
Yes
Check the outdoor unit
power circuit, and repair
any defective part.
power circuit, and repair
any defective part.
Yes
No
Check according to the
proper method for
checking the power circuit
proper method for
checking the power circuit
Is the control voltage being
generated normally?
12V line: 12V or 7V
5V line: 5V
generated normally?
12V line: 12V or 7V
5V line: 5V
Yes
Check the wireless light
receiving unit.
receiving unit.
Do the deflectors perform initial
operation when the power
supply is turned ON after OFF?
operation when the power
supply is turned ON after OFF?
Yes
No
No
Replace the
microcomputer and
oscillator.
microcomputer and
oscillator.
Is the microcomputer clock
signal 10Mhz at pins ⑩ and ⑪
being generated normally?
signal 10Mhz at pins ⑩ and ⑪
being generated normally?
No
Check the reset circuit and
repair any defective part.
repair any defective part.
Is the microcomputer reset
input pinn⑦ “Hi”?
input pinn⑦ “Hi”?
Yes
Replace the control PWB
No
No
Check the AC outlet and
breaker, and repair any
defective part.
breaker, and repair any
defective part.
Is AC220~240V being generated
between terminals A and B on
the indoor unit terminal board
between terminals A and B on
the indoor unit terminal board
Is AC220~240V being
generated at the AC outlet
generated at the AC outlet
No
Is DC35V or 20V being
generated between terminals C
and D on the indoor unit
terminal board?
generated between terminals C
and D on the indoor unit
terminal board?
Is AC220~240V being
generated between
terminals A and B on the
outdoor unit terminal
board
generated between
terminals A and B on the
outdoor unit terminal
board
Yes
Is DC35V being generated
between terminals C and D
on the outdoor unit
terminal board?
between terminals C and D
on the outdoor unit
terminal board?
Yes
Yes
Connect the cables
correctly
correctly
Are C and D connection
cables reversed?
cables reversed?
No
Perform final operation check
Yes
Yes
※1: When not in operation, the unit will enter into a low power standby state, possibly causing a voltage
drop to the 12V and 35V lines as shown
25V~20V
12V~7V