Hitachi RAC-25FPA, Service Manual

Page: 87 / 117

1. Failure phenomenon: The power will not become turned on.
>
Situation
@ǂ
Neither initialization, remote control, nor any other step works on the vane position at power-on.
[ Estimated failure
locations ] · 3.15 A fuse blown out
·
Control power circuit
· Connector loose, wire break
>
Cautions
@
> Diagnosis flow @
Initiating troubleshooting
Replace the 3.15A Fuse of outdoor ele, parts.
Replace the varistor 5 of outdoor ele,parts.
Abnormal
Is the power supply voltage normal?
Normal power supply voltage:230V AC .
Is a voltage of 230V AC applied between the outdoor terminal
tab A-B.
Is a voltage of 32-38V DC applied between the outdoor terminal
tab C-D.
Estimated cause of fuse blowout · Abnormally high voltage applied to the power supply
·
Indoor fan motor out of order
· Power circuit out of order
· Before work, check the power supply voltage. An abnormal voltage may be being supplied in
some rare occasions due to a defect in the indoor wiring (a wire break in the neutral wire of the
single-phase 3-wire power supply).
· If the 3.15 A fuse has blown out, eliminate the cause of the fuse blowout. Otherwise, there will occur
another fuse blowout.
· If the 3.15 A fuse has blown out due to an abnormally high voltage to the power supply, the varistor
(VA001) will deteriorate and become destroyed as well.
·
On a repair service visit due to the failure phenomenon of "The power will not become turned on",
take a "3.15 A fuse" and a "varistor" with you.
Power cord line confirm.
The terminal confirm.
Replace the control P.W.B.
Indoor/Outdoor F-cable’s C-D is correct
connected?
Is the CN3 securely connected?
Replace the terminal.
Get the indoor wiring back to its
normal condition, then conduct
a final check.
F-cable Fix
Check the outdoor
ele. parts.
Yes No
No
No
No
Yes
Yes
Yes
Normal
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