Hitachi RAK-50PPD Service Manual page 136

SUMMARY OF TROUBLESHOOTING METHOD FOR INDOOR UNIT
MODEL : RAK-50PPD / RAK-60PPD
Test Run
1) Power ON the unit and
wait for 3 seconds.
2) Press and hold temp.
switch for 5 seconds or
longer.
Checking the connection of 1, 2, 3 terminal to the indoor.
1) Power ON the unit.
2) After around 1 minute, check the AC voltage between terminal as below table.
Voltage value between terminal
Connection condition
1 to 2
All connection OK 240V
Terminal 1 no connection 240V
Terminal 2 no connection 240V
Terminal 3 no connection 240V
Checking the Terminal fuse continuity.
1) Power off the unit.
2) Disconnect the thermistor wire from
CN3 of MAIN P.W.B
3) Check the resistance value between
the wire.
It shall be almost 0Ω.
Checking all the fuse continuity.
There are 1 fuses inside the MAIN
P.W.B.
1) Power off the unit.
2) Check the continuity of FU1 fuse:
It shall be (3.15A) .
Checking the Room temperature thermistor.
1) Power off the unit.
2) Disconnect the thermistor wire from
CN2 of Indicating P.W.B
3) Check the resistance value between
the lead of thermistor.
It shall be around 10kΩ ± 1kΩ.
Outdoor LD301
indication
2 to 3 1 to 3
around 0.3V 240V Off or 1 time blink
0.1-0.4V 240V 9 times blink
100 - 120V 120-140V 9 times blink
0.1-0.4V 240V 9 times blink
Fan Motor Check
(+) Red (Pin1) &
(-) Black(Pin4)
(+) White (Pin5) &
(-) Black(Pin4)
(+) Yellow (Pin6) &
(-) Black(Pin4)
(+) Blue (Pin7) &
(-) Black(Pin4)
(+) Positive probe
Checking the Heat Exchanger thermistor.
1) Power off the unit.
2) Disconnect the thermistor wire from
CN4 of MAIN P.W.B.
3) Check the resistance value between
the wire of thermistor.
It shall be around 10kΩ ± 1kΩ.
Operation
Resistance
> 2MΩ/OL 360VDC
35kΩ~40kΩ 15VDC
230kΩ~250kΩ 3~6VDC
> 2MΩ/OL 7.5VDC
(-) Negative probe
Checking the vertical stepping motor.
1) Power off the unit.
2) Disconnect the thermistor wire from
3) Check the resistance value between
-
Checking the horizontal stepping motor.
1) Power off the unit.
2) Disconnect the thermistor wire from
CN11 or 14 of MAIN P.W.B.
3) Check the resistance value between
pin 1 and 5.
It shall be around 195 ± 5Ω.
( - side of multimeter probe)
CN16
( + side of multimeter probe)
CN12 of MAIN P.W.B.
pin 1 and 5.
It shall be around 195 ± 5Ω.
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