Startup Control - Midea M thermal A Mono Series Service Manual

3 Startup Control

3.1 Compressor Startup Delay Control
In initial startup control and in restart control (except in oil return operation and defrosting operation), compressor startup
is delayed such that a minimum of the set re-start delay time has elapsed since the compressor stopped, in order to
prevent frequent compressor on/off and to equalize the pressure within the refrigerant system. The compressor re-start
delays for cooling and heating modes are set on the user interface. Refer to the M thermal Mono Engineering Data Book
Part 3, 7.5 COOL MODE SETTING Menu and Part 3, 7.6 HEAT MODE SETTING Menu .
3.2 Compressor Startup Program
In initial startup control and in re-start control, compressor startup is controlled according to outdoor ambient
temperature. There are two startup programs which both have 60 second stage for compressor to startup. Once the 60
second stage is complete, the program proceeds to the subsequent stages in a step-by-step fashion and exits when the
target rotation speed has been reached.
3.3 Startup Control for Heating and Domestic Hot Water Operation
Table 3-3.1: Component control during startup in heating and domestic hot water modes
Component
Inverter compressor
DC fan motor
Electronic expansion valve
Four-way valve
3.4 Startup Control for Cooling Operation
Table 3-3.2: Component control during startup in cooling mode
Component
Inverter compressor
DC fan motor
Electronic expansion valve
Four-way valve
202008
Wiring diagram label 18/22/26/30kW
COMP
FAN_UP / FAN_DOWN
EEV1
ST
Wiring diagram label 18/22/26/30kW
COMP
FAN_UP / FAN_DOWN
EEV1
ST
Midea CAC Confidential
M thermal Mono
Control functions and states
Compressor startup program selected according to
ambient temperature and discharge temperature
Fan runs at higher speed
304 steps
On
Control functions and states
Compressor startup program selected according to
ambient temperature and discharge temperature
Fan runs at higher speed
304 steps
Off
13