Hitachi RCUE40AG2 Service Manual page 82

Control System
6. Prevention control for freezing
If it is detected that refrigerant inlet temperature of water side heat exchanger is decreased, expansion valve
shall be open so that decrease of refrigerant temperature is prevented, which leads to anti-freeze in the
water side heat exchanger.
a) Normal Control
Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor Compressor
Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start Operation start
Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on Power on
Standby at 10 pulse
Zero point adjustment at Power ON
b) Zero Point Adjustment (imaged fi gure)
Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control Superheat control
Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF Thermo OFF
c) Prevention Control for Discharge Refrigerant Gas Overheat (imaged fi gure)
pag. 80
SMGB0003 rev.0-01/2007
At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload, At fi nishing starting unload,
Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree Open at a certain degree
During super During super During super During super During super During super During super During super During super During super During super During super During super During super During super During super During super
heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control heat control
Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload Opening degree for starting unload
If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h If compressor is not stop over 200h
Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON Thermo ON
Zero point adjustment during Thermo OFF Zero point adjustment during Thermo OFF
If 24 h has passed since the last adjustment
Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control Re-activation of Td control
Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C Release if Td is below 70°C
Fix the opening if Td is over 100°C
(Td control)
Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop Thermo OFF or stop
Standby at 10 pulse
Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min Re-start in 3min
Forced zero point adjustment
Compressor discharge gas Compressor discharge gas
refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td) refrigerant temp. (Td)
Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve Opening of expansion valve
Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC Opening more if Td is over 107ºC
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