Control System - Hitachi RAS-2-HVNP Service Manual

5. Control System

Index
5.1. Device control system ......................................................................................................................... 118
5.2. Outdoor units PCB .............................................................................................................................. 120
5.2.1. RAS-(2-2.5)HVNP / RAS-3HVNC ............................................................................................................ 120
5.2.2. RAS-3HVNPE .......................................................................................................................................... 121
5.2.3. RAS-(4-6)H(V)NPE .................................................................................................................................. 122
5.2.4. RAS-(4-6)H(V)NCE ................................................................................................................................. 123
5.2.5. RAS-(8-10)HN(P/C)E .............................................................................................................................. 124
5.2.6. RAS-12HNP - Preliminary data ............................................................................................................... 125
5.2.7. RAS-12HNC - Preliminary data ............................................................................................................... 126
5.3. Protection and safety control ............................................................................................................... 127
5.4. Standard operation sequence ............................................................................................................. 128
5.4.1. Cooling operation .................................................................................................................................... 128
5.4.2. Dry operation ........................................................................................................................................... 130
5.4.3. Heating operation .................................................................................................................................... 132
5.4.4. Automatic cooling and heating operation ................................................................................................ 134
5.4.5. Defrost operation control ......................................................................................................................... 135
5.5. Standard control functions................................................................................................................... 138
5.5.1. Freezing protection during cooling process or dry operation ................................................................... 138
5.5.2. Prevention Control for High Pressure Increase during Cooling Operation .............................................. 139
5.5.3. Prevention control for excessively high discharge gas temperature ....................................................... 140
5.5.4. Activation for protection device control .................................................................................................... 141
5.5.5. Preheating control of compressor ............................................................................................................ 142
5.5.6. Prevention control for high pressure increase ......................................................................................... 143
117
SMGB0079 rev.0 - 01/2013
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. C o n t r o l S y s t e m
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