Midea MSMTAU-09HRFN8-QRD6GW, Service Manual

Page: 28 / 53

26
fan speed reduces to 40%;
-When T1-Tsc is lower than or equal to 0°C, fan
speed reduces to 20%;
-When T1-Tsc is lower than or equal to -0.5°C,
fan speed reduces to 1%.
2.2 Rise curve
-When T1-Tsc is higher than 0°C, fan speed
increases to 20%;
-When T1-Tsc is higher than 0.5°C, fan speed
increases to 40%;
-When T1-Tsc is higher than 1°C, fan speed
increases to 60%;
-When T1-Tsc is higher than 1.5°C, fan speed
increases to 80%;
-When T1-Tsc is higher than 4°C, fan speed
increases to 100%.
9.4.2.4 Condenser Temperature Protection
T3
Resume
Decrease
Hold
Increase
Off
(T4< 53)
(53 T4< 54)
(T4 54)
(54 T4< 55)
When the condenser temperature exceeds a
configured value, the compressor ceases
operations.
9.4.2.5 Evaporator Temperature Protection
When evaporator temperature drops below a
configured value, the compressor ceases
operations.
9.4.3 Heating Mode
9.4.3.1 Compressor Control
1.Reach the configured temperature
1.1 If the following conditions are satisfied, the
compressor ceases operation.
•
While calculated frequency(fb) is less than
minimum limit frequency(FminC).
•
When protective time is more than or equal
to ten minutes.
•
When T1 is higher than or equal to
Tsc+setting temperature(It is 2°C usually.)
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
2. When the current is higher than the
predefined safe value, surge protection is
activated, causing the compressor to cease
operations.
9.4.3.2 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.
9.4.3.3 Indoor Fan Control
1. In heating mode, the indoor fan operates
continuously. The fan speed can be set to
1%-100%, or mute.