How it Works
Hitachi
Loading...
RAS-70YHA4

Hitachi RAS-80YHA4, RAS-70YHA4 Summary Of Troubleshooting Method

SUMMARY OF TROUBLESHOOTING METHOD FOR INDOOR UNIT
MODEL : RAS-70YHA4~80YHA4
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.
Connection condition
Voltage value between terminal Outdoor LD301
1 to 2 2 to 3 1 to 3
240V 240V 240V 240V
around 0.3V
0.1-0.4V
100 - 120V
0.1-0.4V
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.
indication
240V 240V
120-140V
240V
Off or 1 time blink
9 times blink 9 times blink 9 times blink
Fan Motor Check
(+) Red (Pin1) & (-) Black(Pin4)
(+) White (Pin5) & (-) Black(Pin4)
(+) Yellow (Pin6) & (-) Black(Pin4)
(+) Blue (Pin7) & (-) Black(Pin4)
(+) Positive probe (-) Negative probe
Resistance
> 2MΩ/OL 360VDC
35kΩ~40kΩ 15VDC
230kΩ~250kΩ 3~6VDC
> 2MΩ/OL 7.5VDC
Operation
( - side of multimeter probe)
CN16
( + side of multimeter probe)
Checking the vertical stepping motor.
1) Power off the unit.
2) Disconnect the thermistor wire from CN12 of MAIN P.W.B.
3) Check the resistance value between pin 1 and 5.
It shall be around 195 ± 5Ω.
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 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.
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.
SUMMARY OF TROUBLESHOOTING METHOD FOR OUTDOOR UNIT
MODEL : RAC-70YHA4 AND RAC-80YHA4
Checking the IPM IC of IPM P.W.B.
1) Power off the unit.
2) Disconnect compressor wire connector between compressor to IPM P.W.B.
3) Check the diode value between below point :-
a) Terminal U, V, W (+ side of multimeter probe) to
Terminal P (WHT wire) ( - side of multimeter probe). It shall be around 0.40 to 0.43.
b) Terminal N (BLK wire) (+ side of multimeter probe) to
Terminal U, V, W ( - side of multimeter probe)
It shall be around 0.40 to 0.43. **During normal running, DC voltage between below point are:­a) Terminal P & Terminal N shall be around 320V b) Terminal U, V, W (+ side of multimeter probe) to Terminal N
( - side of multimeter probe) shall be around 160V.
Checking the compressor motor winding.
1) Power off the unit.
2) Disconnect compressor wire connector between compressor to IPM P.W.B.
3) Check the resistance value between WHT, YEL,
WHT
COMPRESSOR
WHT
YEL
YEL
RED RED
U V W
CN21(BLU)
CN22(BLU)
IPMP.W.B
P(+)
WHT
TAB5
RED wire of compressor wire. It shall be same on all
BRN
TAB4
terminals between 1Ω to 3Ω.
TAB3
Checking the reactor winding.
1) Power off the unit.
YEL
REACTOR
2) Disconnect YEL and BRN wire at TAB3 and TAB4 from MAIN P.W.B.
3) Check the resistance value between YEL & BRN wire of
3AFUSE
reactor. It shall be around
0.01Ω to 0.1Ω.
** During normal running, DC voltage between TAB 3 and TAB4 shall be 17V to 20V.
Checking all the fuse continuity.
There are 5 fuses inside the MAIN
SWITCHING
POWER
CIRCUIT
P.W.B.
1) Power off the unit.
2) Check the continuity of below fuse:
MAINP.W.B
a) F1 (25A) b) F5 (3.15A) c) F6 (3.15A) d) F3 (3A)
e) F4 (2A)
Checking the power source.
1) Power ON the unit.
2) Check the AC voltage from power source between terminal L and N. It shall be around 240 ±10 V
25A
FUSE
3.15AFUSE
BRN BLU BLK
L N
POWERSOURCE
3.15AFUSE
(GRN
&YEL)
1 2 3
TOINDOORUNIT
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.
Connection condition
Voltage value between terminal Outdoor LD301
1 to 2 2 to 3 1 to 3
240V 240V 240V 240V
around 0.3V
0.1-0.4V
100 - 120V
0.1-0.4V
240V 240V
120-140V
240V
Checking the fan motor winding.
1) Power off the unit.
2) Disconnect fan motor wire from CN24 of MAIN P.W.B.
3) Check the resistance value between RED, WHT, BLK wire of fan motor. It shall
be around 20Ω to 50Ω.
**During normal running, DC voltage between RED, WHT, BLK wire of fan motor (+ side of multimeter probe) to Terminal N (R741 leg) (- side of multimeter probe) shall be around 160V.
WHT
DRIVE
CIRCUIT
P
N
GRN1
GRN2
(GRN
&YEL)
CN24
(WHT)
CN15
(WHT)
CN17
(WHT)
CN18
(WHT)
CN20
(WHT)
CN25
(WHT)
CN30
(WHT)
CN27
(WHT)
(RED)
CN10
(RED)
CN9
(BLK/
BLU)
CN8
(WHT)
GRN3
CN2
BLK
U V W
RED
WHT
BLK
EEPROM
TEST
MICON
DRM1 DRM2 DRM3 PSC
B-12V B-0V
N(-)
BLK
WHT
TAB6
TAB7
2AFUSE
POWER
CIRCUIT
RED
WHT
CONNECTION
BLK
TAB8
indication
Off or 1 time blink
9 times blink 9 times blink 9 times blink
CAPAP.W.B
6
Test Run
1) Remove Terminal 3 connection.
2) Power ON the unit and wait for 30 seconds.
3) Press and hold test
switch for 5 seconds.
Checking the expansion valve winding.
1) Power off the unit.
2) Disconnect the expansion valve from
CN15 of MAIN P.W.B.
3) Check the resistance
value between wire of expansion valve as
below:­a) WHT to BRN b) ORN to BRN c) YEL to RED d) BLU to RED
It shall be around
46Ω ± 3.7Ω.
OUTDOOR
MOTOR
Checking the reversing valve winding.
FAN
1) Power off the unit.
2) Disconnect the reversing valve wire from CN2 of
EXPANSION VALVE
MAIN P.W.B.
3) Check the resistance
value between the wire of reversing valve. It shall be around
1.9kΩ.
Checking the outdoor temperature thermistor.
1) Power off the unit.
2) Disconnect the
SELF-CHECK
REVERSING
VALVE
thermistor wire from CN10 of MAIN P.W.B.
3) Check the resistance value between the wire of thermistor.
OUTDOOR
TEMPERATURE
THERMISTOR
DEFROST THERMISTOR
OH
THERMISTOR
It shall be around
1.7kΩ ± 0.3kΩ.
Checking the defrost thermistor.
1) Power off the unit.
2) Disconnect the thermistor wire from CN9 of MAIN P.W.B.
3) Check the resistance
value between the wire of thermistor. It shall be around
1.7kΩ ± 0.3kΩ.
Checking the OH thermistor.
1) Power off the unit.
2) Disconnect the thermistor wire from CN8 of MAIN P.W.B.
3) Check the resistance value between
the wire of thermistor.
It shall be around 25kΩ ± 5kΩ.
Loading...
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use