– 48 –
•
The voltage specification of the power circuit is as follows.
<Check points>
Output
Voltage
Main load
Measuring points
Potential failure modes
spec.
+
–
12V
11-13V
MAIN P.W.B. (CN3, CN4)
R701 (“12V” display)
R006 (“0V” display)
The unit won’t operate
C21 (“12V” display)
J27, J30
MAIN P.W.B. error
5V
4.5-6V
MAIN P.W.B. (CN3, CN4)
D30 anode (“5V” display) R006 (“0V” display)
The unit won’t operate
J25
J27, J30
MAIN P.W.B. error
B-12V
11-16V
Expansion valve
R25 (“B-12V” display)
R25 (“B-0V” display)
LD301 blinks 5 times;
Expansion valve error
15V
14-17V
DC fan motor (CN24)
C06+ side
C06- side
LD301 blinks 3 times,
MAIN P.W.B. (CN3, CN4)
35V
33.5-38V
Indoor unit electrical parts
D20 cathode
J5, J17
Indoor unit won’t operate
(Terminal C,D)
(“C-35V” display)
Terminal D (red line)
Reversing valve (CN2)
Terminal C (blown line)
•
Check each voltage. If each voltage meets the voltage specification above, the power circuit is
normal.
•
If any error is found after checking, remove all loads and recheck each voltage.
If no error is found in this step, the power circuit is normal. Check the removed loads.
If any error is found in this step, the power circuit has any failure. Replace the power P.W.B.
A short-circuited load may cause an output error not only in the load but also in the others. Be sure
to check all outputs of the loads.
Be sure to wait 15 minutes or more in order to discharge all the remaining voltage in the circuit to
connect/disconnect the wiring, otherwise, the components may be damaged.
•
The failures of the loads are as follows.
Failed
output
35V
15V
12V, 5V
Criterion
Connect the cable correctly.
Remove the connection cable and measure the
voltage. If the voltage is correct, check the electrical
parts for the indoor unit.
Remove the CN2 and measure the voltage. If the
voltage is correct, check the reversing valve.
Remove the CN24 and measure the voltage.
(connect the CN3.) If the voltage is correct, check
the DC fan motor.
Also, check the main P.W.B. 1 A fuse for blow out in
this step.
Remove the CN3 and CN4 and meaure the voltage.
If the voltage is correct, check the main P.W.B.
Remove the CN3 and CN4 and meaure the voltage.
If the voltage is correct, check the main P.W.B.
Possible causes
Reversed connection of the cable.
Electrical part for the indoor unit has
a failure.
Short-circuited reversing valve
DC fan motor error
Main P.W.B. error
Main P.W.B. error
Содержание RAC-14EH2
Страница 22: ...RAS 14EH2 CIRCUIT DIAGRAM 20 07K394_RAS 14EH2_020 021_A2_E 2007 10 31 17 19 20 ...
Страница 25: ... 23 button 25 26 26 27 28 26 RAS 14EH2 07K394_RAS 14EH2_023_A3_E 2007 10 31 16 45 23 ...
Страница 92: ... 90 07K394_RAS 14EH2_083 092_E 2007 11 12 09 12 90 ...
Страница 94: ... 92 07K394_RAS 14EH2_083 092_E 2007 11 12 09 12 92 ...
Страница 95: ...HITACHI AW NO 0029E RAS 14EH2 RAC 14EH2 07K394_RAS 14EH2_000cover_E 2007 10 31 17 14 3 ...