Functions And Control - York YH9FXH12BAH FX Series Service Manual

7.Functions and control

7.1 Main functions and control specifications
Including brief introduction to air conditioners of series models and electric control function.
7.1.1 Automatic running
(1) Single cold automatic run mode:
First entering into this mode, the main control "MCU" determines the corresponding work pattern according to the
indoor temperature between cooling mode and blowing mode. When Tr Ts+3 , the unit enters the blowing mode,
outlet air from compressor is off, the automatic wind from fan motor is low, and wind can be set to high, medium or low
by hand. When Tr < Ts +3 , the unit enters the cooling mode and conducts the cooling programme, outlet air from
compressor is on and indoor fan motor run in fixed wind speed.
After entering into this mode,the main control "MCU" determines the corresponding work pattern according to the
indoor temperature between cooling mode and blowing mode. When in the cooling mode, if Tr Ts-3, the unit enters the
blowing mode. When in the blowing mode, if Tr >Ts-3,the unit enters the cooling mode .
(2) Automatic running mode
When the running mode is turned to automation after starting the system, the system will first determine the running
mode according to the current room temperature and then will run according to the determined mode. Tr in the
following selection conditions means room temperature, Ts means setting temperature, Tp means temperature of
indoor coil pipe
a. Tr 23
b. Tr<23
After turning to the automation mode, the running mode can be switched between cooling mode, fan mode and
heating mode according to the change of the indoor ambient temperature. But the automatic conversion between
cooling mode and heating mode must be conducted after 15 minutes.
7.1.2 Indoor temperature control
Temperature control range : 16
Temperature control precision: 1
Compressor can't be controlled by temperature sensor within 2 minutes after it starts
7.1.2.1 Cooling mode:
When Tr> Ts, outdoor fan motor and compressor on, and indoor fan motor run at fixed wind speed. When Tr
outdoor fan motor and compressor off, and when Tr > Ts, outdoor fan motor and compressor are working again .If Tr=Ts,
the indoor fan motor , outdoor fan motor and the compressor's state will not change.
7.1.2.2 Heating mode:
When Tr Ts, compressor, four-ways valve and outdoor fan motor is on, indoor fan
motor runs as in cold blast avoidance mode, and 4 of compensation is added after compressor is started.
When Tr>Ts+5 , compressor is off, and the indoor fan motor runs as in cold blast avoidance mode.
When Tr<Ts+5 , compressor, four-ways valve and outdoor fan motor is on, and the indoor fan motor runs as in the
mode of avoiding cold blast.
7.1.3 Cooling run mode:
temperature control range : 16
running cooling mode
running heating mode
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13
Functions and control
Ts,