Operation Modes And Functions - Midea MSMTAU-09HRFN8-QRD6GW Service Manual

9.4 Operation Modes and Functions

9.4.1 Fan mode
1. When fan mode is activated:
-The outdoor fan and compressor are stopped.
-Temperature control is disabled and indoor
room temperature is displayed.
-The indoor fan speed can be set to 1%~100%,
or auto.
-The louver operations are identical to those in
cooling mode.
-Auto fan: In fan mode, AC operates the
same as auto fan in cooling mode with the
temperature set at 24°C.(Tsc =24°C)
9.4.2 Cooling Mode
9.4.2.1 Compressor Control
1. Reach the configured temperature
1.1 When the compressor runs continuously for
less than 120 minutes.
1.1.1 If the following conditions are satisfied,
the compressor ceases operation.
While calculated frequency(fb) is less than
•
minimum limit frequency(FminC).
While protective time is more than or equal
•
to ten minutes.
While T1 is lower than or equal to
•
(Tsc-CDIFTEMP-0.5°C)
1.2 When the compressor runs continuously for
more than 120 minutes.
1.2.1 If the following conditions are satisfied,
the compressor ceases operation.
• When calculated frequency(fb) is less than
minimum limit frequency(FminC).
• When protective time is more than or equal
to ten minutes.
When T1 is lower than or equal to
•
(Tsc-CDIFTEMP).
1.3 If one of the following conditions is
satisfied, not judge protective time.
Compressor running frequency is
•
more than test frequency.
When compressor running frequency
•
is equal to test frequency, T4 is more
than 15°C or no T4 or T4 fault.
Change setting temperature.
•
Turbo or sleep function on/off
•
Various frequency limit shutdown
•
occurs.
Note: CDIFTEMP is EEPROM setting
parameter. It is 2°C usually.
9.4.2.2 Outdoor Fan Control
The outdoor unit operates at different fan
speeds based on T4 and compressor running
frequency. The actual speed varies between
different outdoor units.
9.4.2.3 Indoor Fan Control
1. In cooling mode, the indoor fan operates
continuously. The fan speed can be set to
1%-100%, or auto.
2. Auto fan
2.1 Descent curve
-When T1-Tsc is lower than or equal to 3.5°C,
fan speed reduces to 80%;
-When T1-Tsc is lower than or equal to 1°C, fan
speed reduces to 60%;
-When T1-Tsc is lower than or equal to 0.5°C,
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