Johnson Controls york YSHC18FSAADG, Service Manual

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Domestic Air Conditioner
5 Functions and control
5.1 main functions and control specifications
Including brief introduction to air conditioners of series models and electric control function.
5.1.1 Automatic running
5.1.1.1 Single cold automatic run mode:
After entering into this mode, the main control “MCU” determines the corresponding work pattern
according to the indoor temperature so as to maintain the preset temperature (the preset temperature is 26 ).
When the indoor temperature is below 26 , 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 the indoor temperature is or above
26 , the unit enters the cooling mode and conducts the cooling programme (the preset temperature is 26 ),
outlet air from compressor is on and indoor fan motor run in fixed wind speed.
5.1.1.2 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 running cooling mode
b. Tr<23 running heating mode
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.
5.1.2 Indoor temperature control
Temperature control range : 16 —30
Temperature control precision: 1
Compressor can’t be controlled by temperature sensor within 2 minutes after it starts
5.1.2.1 Cooling mode:
When Tr> Ts, outdoor fan motor and compressor on, and indoor fan motor run at fixed wind speed. When Tr
Ts, 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.
5.1.2.2 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.
5.1.3 Cooling run mode:
temperature control range :16 —30
temperature control precision: 1
compressor can’t be controlled by temperature sensor within 2 minutes after it starts.
control character: when Tr Ts, outlet air from compressor is on and indoor fan motor run at fixed
wind speed. When Tr Ts, outlet air from compressor is off , and when Tr > Ts, outlet air from compressor
is on.
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YSHC18/24FSAADG
Functions and Control