Hitachi RCUE40AG1-400AG1 User manual

AIR COOLED
WATER CHILLERS
-SCREW TYPE-
Maintenance Instructions.
Service Manual
RCUE40AG1-400AG1 (R407C)
Cooling Capacity 108 kW - 1068 kW

0
TABLE OF CONTENTS
1.TROUBLESHOOTING.................................................................................................................1
1.1. OUTLINE OF FAILURE DIAGNOSIS.............................................................................................................2
1.2. ALARM INDICATION.................................................................................................................................3
1.3. FAILURE DIAGNOSIS METHOD4
1.4. ANALYSIS AND COUNTERMEASURE OF ABNORMAL RUNNING .......................................................................21
2. ELECTRICAL WIRING................................................................................................................27
2.1. CUSTOMER WIRING .................................................................................................................................27
2.2. WIRING DIAGRAM ....................................................................................................................................29
2.3. MAIN CIRCUIT BOARD ..............................................................................................................................41

TROUBLESHOOTING 1
/
1
1TROUBLESHOOTING
1.1. OUTLINE OF FAILURE DIAGNOSIS
In the case of abnormality, alarm lamp of remote control and alarm LED on the control panel are ON. And segment indication on
the control panel is flickering. For stopping the unit, put it into stop operation without power OFF.
Alarm occur
Segment Indication:
Abnormality Code Flickering.
Alarm Indication: ON
(Local Side)
Remote Control Run Indication:
ON
Remote Control Alarm Indication: ON
(Remote Side)
Stop Operation
Is abnormality code
in segment indication
confirmed?
Abnormality code is indicated
by indication mode of alarm
Occurence Data.
Abnormality code is indicated
in the segment indication.
Take proper measure
according to the alarm position
NOTE:
- After the stop operation, alarm indication is turned off and initial status 88 is displayed. And then abnormality code, which
activated before is indicated by “Indication Mode of Alarm Occurrence Data”.
- When the power turns off and turns on, the indication is initial status. And then abnormal code, which activated before is
indicated by “Indication Mode of Alarm Occurrence Data”
Yes
No

1/2 TROUBLESHOOTING
1.2. ALARM INDICATION
7-Segment indication shows the following abnormalities
Unit does not run Check the power source
Check the 7-segment
indication
Alarm Code
No.1~6 cycles Description of abnormality
[]~[]Excessively Low Pressure
[]~[]Low Pressure Protection by Suction Gas Thermistor
[]~[]Excess Low Temperature of Cooler Inlet Refrigerant
[]~[]Freezing Protection Control by Cooler Inlet Refrigerant Temperature and excess low suction pressure (retry
operation)
[]Activation of Freezing Protection Control
[]~[]Activation of High Pressure Switch
[]~[]Activation of Discharge Gas Thermostat
[]~[]Activation of Compressor Internal Thermostat
[]~[]Phase Abnormally
[]~[]Error communication between Ctrl. PCB and Fan Speed Ctrl. PCB’s (Low Ambient Fan Speed Ctrl. Option)
[]~[]Failure of Thermistor set before Expansion Valve (Open / Short)
[]~[]Activation of Fan Motor Internal Thermostat
[]Failure of Ambient Temperature Thermistor (Open / Short)
[]~[]Failure of Cooler Inlet Refrigerant Thermistor (Open/Short)
[]~[]Failure of Discharge Gas Thermistor (Open/Short)
[]~[]Failure of water oulet temperature thremistor i cooler siter (Open / Short)
[]~[]Failure of Suction Gas Thermistor (Open / Short)
[]~[]Failure of Discharge Gas Pressure Sensor (Open / Short)
[]~[]Failure of Suction Gas Pressure Sensor (Open / Short)
[]Error communication between Ctrl. PCB (PCBC1, PCBC2)
[]Failure of Water Inlet Temperature (Open / Short)
[]Failure of Water Outlet Temperature Thermistor (Open / Short)
[]Failure of Water Outlet 2 Temperature Thermistor (Open/Short)
[]Failure of Water Outlet 3 Temperature Thermistor (Open/Short)
[]Malfunction
[]~[]Activation of Differential Pressure Control
[]~[]Activation of Thermal Relay for Compressor
[]~[]No Feedback Signal from Water Pump
[]~[]Alarm of Excessively High Water -Temperature
[]Alarm of Water Failure (Differential Water Pressure Switch Option)
[]Activation of Additional Protection Device (Option)
" " - " " : Flickering. XX - XX : SEG1-SEG2
With indication
Without indication

TROUBLESHOOTING 1
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3
1.3. FAILURE DIAGNOSIS METHOD
1.3.1. GENERAL CHECK OF FAILURE DIAGNOSIS.
In the case of no segment indication, unit cannot operate.
Is 220-240V supplied
to the unit?:
Check the power
source switch
Is 220-240V supplied to
transformer primary side? Is fuse broken? Replace fuse
Wiring check
and repair
Is R phase or S
phase failure?
Wiring check
Is 30V in PIN1~PIN2,
16.3V IN PIN3~PIN4,
19.6V IN PIN5~PIN6 of the
printed circuit board for CPU
(PCBc) connector CN2A
Is the wiring of
transformer broken? Replace
transformer
Wiring check
Connector check
Is the wiring of
transformer broken?
Replace
transformer
Wiring check
Connector check
Is 26.7V in PIN1~PIN2,
17.6V in PIN3~PIN4,
17.6V in PIN5~PIN6 of the
printed circuit board for CPU
(PCBc) connector CN2B
and CN2C
Is voltage in each test PIN of printed circuit board
for CPU
5 V part VCCO5-GND1
V5B-GND1
VCCO5N-GND1
VCCR-GND1
+15V part VCC15T-GND1
- 15V part VCC15T-GND1
24V part VCC24-GND1
VCC24T-GND1
Power Source Circuit
Malfunction
Replace Printed
Circuit Board for
CPU (PCBC)
Are connector FCN1, FCN2
on the printed circuit board for
CPU (PCBC) and Printed
Circuit Board for Display and
Operation (PCBA, PCBB)
correctly connected and
checked loose connection?
Connector Repair
Check Printed
Circuit Board for
Display and
Operation (PCBA,
PCBB)
Check Printed
Circuit Board for
CPU (PCBC)
No
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
Yes
No
No
No
No
No
Yes
Yes
No

1/4 TROUBLESHOOTING
![] ~ [] Excessively Low Suction Pressure
In case of the suction pressure is less than 0.31 Mpa during 90 seconds, the unit will stop at once and indicate
“[]~[]”. 3 minuts later, the unit will start again. This Alarm code is indicated when it occurs 3 times during 30
minutes (It will retry until 2 times.).
Is connector CN 29Ps on the
printed circuit board for relay
(PCBD) correctly connected?
Wiring Check
No
Shortage of Refrigerant Gas Leakage
Clogging of expansion valve
Clogging of strainer
Clogging of low pressure side pipe
Stop Valve malfunction
Shortage of Water
Pump reverse rotation
A
ir mixed
Deposits on Water Cooler Plates
Clogging of Water Strainer
Yes

TROUBLESHOOTING 1
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5
![] ~ [] Low Pressure Protection by Suction Gas Thermistor
This alarm code is indicated when the suction temperature is lower than -2°C during 10 seconds.
Is the wiring of connector in the
Printed Circuit Board for Relay
(PCBD) correct?
Plug correctly and
repair wiring
Replace thermistor
Pull out connector and measure
thermistor resistance. Is
resistance correct?
Check Printed Circuit Board
for Relay (PCBD)
Thermistor
resistance
(KΩ)
Temperature (°C)
Thermistor for Suction Gas Temperature
characteristics
Clogging of water strainer
Yes
No
Yes
Check the water flow rate.(Check temperature
of inlet and outlet.
)
Pump reverse rotating check
Check the air mixing
Clogging of expansion valve
Clogging of strainer
No
Check chilled water thermostat setting value
(Within the working range)
Shortage of refrigerant Gas Leakage
Clogging of low pressure pipe
Malfunction of Check valve
Yes
Malfunction of Expansion Valve

1/6 TROUBLESHOOTING
![]~[] Excess Low Temperature of Cooler Inlet Refrigerant
In case of the cooler inlet refrigerant temperature is lower than -3°C during 10 seconds, the unit will stop at once and indicate
“[]~[]”. 3 minutes later, the unit will start again. This alarm code is indicated when it occurs 3 times during 30
minutes (It will retry until 2 times)
Is connector CN27Tr2 on the
printed circuit board for Relay
(PCBD) correctly connected?
Plug correctly and
repair wiring
Pull out connector and measure
thermistor resistance.
Is resistance correct? Replace Thermistor
Check printed circuit board for
Relay (PCBD)
No
Yes
Yes
No
Yes
Check water flow 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 unit working range)
Shortage of Refrigerant Gas
Leakage
Clogging of low pressure side pipe
Clogging of expansion valve
Check Valve Malfunction
Expansion Valve Malfunction