Hitachi RCUE40AG2 Service Manual page 124

Troubleshooting

Alarm code


[Alarm Stop Reason]
- Chilled water temperature is lower than
2°C.(standard unit) (only cooling operation)
- PCB PCN13 wiring is broken.
C
*"13-13" : for 1 cycle unit or if alarm
is detected in inlet water temperature
Thermistor or PCN13 wiring is broken.
"C1-13 ~ C5-13": It is detected in outlet
water temperature in more than 2 cycle
units.
Is connectors on the
Printed Circuit Board
correctly connected?
Yes
Pull out connector and
measure thermistor
resistance
Is resistance correct?
Yes
Yes
Check printed circuit
board for CPU (PCB )
C

NOTE:
One inlet temperature Themistor is installed in each unit.
−
Two outlet temperature Thermistors are installed in every heat exchanger in water side.
−
The below table shows the relation between Thermistor and alarm indication as well as
−
connecting Printed Circuit Board (PCB).
pag. 122
SMGB0003 rev.0 - 01/2007
Activation of Freeze Protection Control
[PCB Monitoring Position]
No
No
PCB (CPU PCB) CN3 (for inlet), CN4 (for No. 1 cycle
C
outlet), CN6 (for No. 2 cycle outlet), CN7 (for No. 3 cycle
outlet)
PCB (I/O PCB) CN23Te2 (for No. 1 cycle protection)
D1
PCB (I/O PCB) CN23Te2 (for No. 2 cycle protection)
D2
PCB (I/O PCB) CN23Te2 (for No. 3 cycle protection)
D3
PCB (CPU PCB) PCN13
C
Plug correctly and
repair wiring
Replace Thermistor
Check water fl ow rate (Check the
temperature of Inlet and Outlet)
Check pump reverse rotation
Check water strainer clogging
Check air mixing
Check Chilled water thermostat setting value
(It shall be within the working range)