Hitachi RAF-25RPA Service Manual page 87

1. Failure phenomenon: The power will not become turned on.
Neither initialization, remote control, nor any other step works on the vane position at power-on.
Situation
[ Estimated failure
locations ]
Cautions
Diagnosis flow
Initiating troubleshooting
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.
Is the CN3 securely connected?
Replace the control P.W.B.
・ 3.15 A fuse blown out
・ Control power circuit
・ Connector loose, wire break
・ 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.
Normal
Yes
Yes
Yes
Estimated cause of fuse blowout ・ Abnormally high voltage applied to the power supply
Abnormal
Replace the 3.15A Fuse of outdoor ele, parts.
Replace the varistor 5 of outdoor ele,parts.
No
No
No
87
・ Indoor fan motor out of order
・ Power circuit out of order
Get the indoor wiring back to its
normal condition, then conduct
a final check.
Power cord line confirm.
The terminal confirm.
Indoor/Outdoor F-cable's C-D is correct
connected?
Yes
Check the outdoor
F-cable Fix
ele. parts.
Replace the terminal.
No