Protection Controls - Hitachi RCUE40AG2 Service Manual

Control system

4.17.3. Protection Controls

This series has a protection control to resolve abnormal status before reaching to the alarm status, occurrence.
Control Name Conditions
High pressure
High pressure ≧2.6MPa
protection
Cooling only: Cooling only:
Low presssure
Low pressure ≦0.333MPa
protection (1)
Heating:
<COOLING>
Low pressure Low pressure ≦ ≦ 0.314MPa
Cooling only: Cooling only:
Low pressure ≦0.333MPa
Low presssure
protection (2) Heating:
<COOLING>
Low pressure ≦0.314MPa
90 sec 90 sec
Protection of
Discharge gas refrigerant
overheat of
temp≧130°C
discharge gas
1min
temperature
Prevention of
Actuation of internal Thermo of
overheat of
motor for compressor
compressor
Prevention of Prevention of
Inlet refrigerant temperature
decrease of
of water side heat exchanger
evaporating
≦–4.5°C
temperature (1)
3 sec
<COOLING> <COOLING>
Prevention of Prevention of
Inlet refrigerant temperature
decrease of
of water side heat exchanger
evaporating
≦–5.5°C
temperature (2)
10 sec
<COOLING> <COOLING>
Prevention of
Inlet refrigerant temperature
decrease of
of water side heat exchanger
evaporating
≦–6.5°C
temperature (3)
3 sec
<COOLING>
Suction refrigerant gas
Anti-freezing (1)
temperature ≦–2°C
<COOLING>
10 sec
Anti-freezing (2)
Chilled water outlet temperature
<COOLING> ≦2.5°C
Protection of High pressure – low
pressure difference pressure≦0.3MPa
Prevention of
excess increase
of warm water Warm water temperature ≧65°C
temperature
<Compressor Stop>
pag. 81
SMGB0003 rev.0-01/2007
Contents
Hold after load-down 10 second
output
When it is continued for 1 min,
hold after load-down 10 second
output
0.314MPa
-Compressor stop: retry code
[Cn-P6]
-Re-start in 3 min
(alarm: 3 times in 30min)
-Compressor stop: retry code -Compressor stop: retry code
[Cn-P5]
-Re-start in 3 min
(alarm: 3 times in 90min) (alarm: 3 times in 90min)
-Compressor stop: retry code -Compressor stop: retry code
[Cn-P5]
-Re-start at internal Thermo
restart
(alarm: 3 times in 60min) (alarm: 3 times in 60min)
-output of fan inverter frequency
6Hz
-Fan inverter frequency is 20Hz at
high pressure≧1.8MPa
Hold after output of load-up 10
second
-Compressor stop: retry code
[Cn-P6]
-Re-start in 3 min
(alarm: 3 times in 30min)
-Compressor stop: retry code
[Cn-P6]
-Re-start in 3 min
(alarm: 3 times in 30min)
Hold after output of load-down 10
second
Hold after output of load-up 12
second
-Pump stop
-Alarm output
-[PU-PU] is fl ickering in the
segment
Release conditions
30 min and High pressure < 2.5MPa
10 min and --Cooling only:
Low pressure≧0.363MPa
-
-
-
30 min or high pressure≧2.0MPa during
fan is fi xed at 20Hz
30 min
-
30 min
High pressure – low pressure > 0.3MPa
1min
Warm water temperature < 60°C
(Automatic release of alarm)
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