Airwell AWAU-YHD009-H11, Service Manual

Page: 26 / 62

CONTROL SYSTEM
SM HHD 1-A.1 GB 12-1
12.
CONTROL SYSTEM
12.1 Electronic Control
12.1.1 Abbreviations
Abbreviation Definition
A/C Air Condition
BMS Building Management System
PWR System Power
CTT Compressor Top Temperature sensor
DCI DC Inverter
EEV Electronic Expansion Valve
HE Heating Element
HMI Human Machine Interface
HST
Heat Sink Temperature sensor
Hz
Hertz (1/sec)
– electrical frequency
ICT Indoor Coil Temperature (RT2) sensor
IDU Indoor Unit
MCU Micro Controller Unit
OAT Outdoor Air Temperature sensor
OCT ODU Coil Temperature sensor
ODU Outdoor Unit
OFAN Outdoor Fan
PFC Power Factor Corrector
RAC Residential A/C
RAT
Room Air Temperature sensor
RC
Reverse Cycle (Heat Pump)
RCT Remote Control Temperature sensor
RGT Return Gas Temperature sensor
RPS Rounds per second (mechanical speed)
RV Reverse Valve
SB,STBY Stand By
SUCT Compressor Suction Temperature sensor
S/W Software
TBD To Be Defined
TMR Timer
12.1.2 System Operation Concept
The control function is divided between indoor and outdoor unit controllers. Outdoor unit is the system
‘Master’, requesting the indoor unit for cooling/heating capacity supply. The indoor unit is the system
‘Slave’ and it must supply the required capacity unless it enters into a protection mode avoiding it
from supplying the requested capacity.
Target frequency is transferred via indoor to outdoor communication, and the caculation is based on
room temperature and set point temperature.
12.1.3 Compressor Frequency Control
The Compressor Frequency Control is based on the PI scheme.