Hitachi UTOPIA RAS-4HVRP2E - Control System

5 Control System
SMGB0136 rev.0 - 07/2021
79
5
Index
5.1 Device control system ...........................................................................................................................80
5.1.1 RAS-3HVRC2 ................................................................................................................................................ 80
5.1.2 RAS-(4-6)H(V)(R/N)(C/P)2E ......................................................................................................................... 81
5.1.3 Outline of the control system ......................................................................................................................... 82
5.2 Outdoor units Printed circuit board (PCB) ............................................................................................. 84
5.2.1 RAS-3HVRC2 ................................................................................................................................................ 84
5.2.2 RAS-(4-6)H(V)(R/N)(P/C)2E ......................................................................................................................... 85
5.3 Protection control ..................................................................................................................................87
5.3.1 Protection control code on 7-segment display .............................................................................................. 87
5.3.2 Activating condition of protection control code .............................................................................................. 88
5.4 Control and safety devices .................................................................................................................... 93
5.5 Standard operation sequence RAS-3HVRC2 and RAS-(4-6)H(V)(R/N)(C/P)2E .................................. 94
5.5.1 Cooling operation .......................................................................................................................................... 94
5.5.2 Dry operation ................................................................................................................................................. 96
5.5.3 Heating operation .......................................................................................................................................... 98
5.5.4 Defrost operation RAS-3HVRC2 ................................................................................................................. 100
5.5.5 Defrost operation RAS-(4-6)H(V)(R/N)(C/P)2E ........................................................................................... 101
5.6 Standard control functions...................................................................................................................103
5.6.1 Freezing protection during cooling process or dry operation ...................................................................... 103
5.6.2 Prevention control for excessively high discharge gas temperature ........................................................... 104
5. Control System