Midea M thermal A Mono Series - 4 Normal Operation Control

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M thermal Mono

202008 13

Part 3

Control

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 Wiring diagram label 18/22/26/30kW Control functions and states

Inverter compressor COMP

Compressor startup program selected according

ambient temperature and discharge temperature

DC fan motor FAN_UP / FAN_DOWN

Fan runs at higher speed

Electronic expansion valve EEV1

304 steps

Four-way valve ST

3.4 Startup Control for Cooling Operation

Table 3-3.2: Component control during startup in cooling mode