Hitachi Set Free mini-HNRQ1 Series, Service Manual

Page: 112 / 187

105
3. Procedures for Checking
3.1 Checking Method for Outdoor Unit PCB of 3~6.5HP
(1) Checking Power Circuit of Outdoor Unit PCB
Check the power circuit on O.U.PCB in following procedures. Refer to the figure on next page about the
positions of LEDs, fuses, and check points. Refer check points by a circuit tester and judgment value as well.
●
Pay attention to an electric shock when the voltage is measured by a circuit tester.
● Do not contact the test lead to unspecified check points when measuring by circuit tester. It may cause
failure of terminal and circuit tester.
●
When the voltage is measured by a circuit tester, the range should be set within the DC voltage
measurement. If the setting is not correct, it may cause failure of O.U.PCB and circuit tester.
*1) The following table shows the check points and the normal range of voltage in case that the voltage on
O.U.PCB is measured by a circuit tester. The setting of circuit tester shall be set within the DC voltage
measurement range when the following voltages are measured.
Check Point
Normal Range (V)
(+) Side of Tester (-) Side of Tester
5V
GND
4.8VDC ~ 5.1VDC
12V 10.5VDC ~ 13.5VDC
CAUTION
!
Turn ON outdoor unit
LED1 (Red) is turned ON.
Is fuse FU1 or
FU2 blown out?
Change the fuse
Yes
No
AC Power is lower than
90% of the rated voltage
Check the voltage
Failure of AC Power
Circuit
DC5V-Driver is applied
b5V and GND.*1)
DC5V-Driver system is
normal.
DC12V is applied between
+12V and GND.*1)
DC12V system is normal.
Check is completed
Power circuit is normal.
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
TROUBLESHOOTING