Safety Features; Basic Functions; Abbreviation; Fan Mode - Mars Comfort-Aire Century VCD-SA Series Service Manual

Service Manual - VCDxxSA

2. Safety Features

Compressor three-minute delay at restart
Compressor functions are delayed for up to ten seconds
upon the first startup of the unit, and are delayed for up
to three minutes upon subsequent unit restarts.
Automatic shutoff based on discharge temperature
If the compressor discharge temperature exceeds a certain
level for nine seconds, the compressor ceases operation.
Inverter module protection
The inverter module has an automatic shutoff mechanism
based on the unit's current, voltage, and temperature.
If automatic shutoff is initiated, the corresponding error
code is displayed on the indoor unit and the unit ceases
operation.
Indoor fan delayed operation
• When the unit starts, the indoor fan will operate after
a period of setting time.
• If the unit is in heating mode, the indoor fan is
regulated by the anti-cold wind function.
Compressor preheating
Preheating is automatically activated when T4 sensor is
lower than setting temperature.
Sensor redundancy and automatic shutoff
• If one temperature sensor malfunctions, the air
conditioner continues operation and displays the
corresponding error code, allowing for emergency use.
• When more than one temperature sensor is
malfunctioning, the air conditioner ceases operation.

3. Basic Functions

3.1

Abbreviation

Unit element abbreviations
Abbreviation Element
T1 Indoor room temperature
T2 Coil temperature of evaporator
T3 Coil temperature of condenser
T4 Outdoor ambient temperature
TP Compressor discharge temperature
TS Setting temperature
Tsc Adjusted setting temperature
In this manual, such as CDIFTEMP, HDIFTEMP2, TCE1,
TCE2...etc., they are well-setting parameter of EEPROM.
3.2

Fan Mode

When fan mode is activated:
• The outdoor fan and compressor are stopped.
• Temperature control is disabled and no temperature
setting is displayed.
• The indoor fan speed can be set to low, medium, high,
turbo and auto.
• Auto fan: In fan-only mode, AC operates the same as
auto fan in cooling mode with the temperature set at
24°C.
3.3

Cooling Mode

3.3.1
Reach the configured temperature:
1) When the compressor runs continuously for less than
120 minutes.
• If the following conditions are satisfied, the
compressor ceases operation.
• Calculated frequency(fb) is less than minimum limit
frequency(FminC).
• Compressor runs at FminC more than ten minutes.
• T1 is lower than or equal to (Tsc-CDIFTEMP-0.5°C)
2) When the compressor runs continuously for more than
120 minutes.
• If the following conditions are satisfied, the
compressor ceases operation.
• Calculated frequency(fb) is less than minimum limit
frequency(FminC).
• Compressor runs at FminC more than 10 minutes.
• When T1 is lower than or equal to (Tsc-CDIFTEMP).
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 T4 fault.
• Change setting temperature.
• High or sleep function on/off
• Various frequency limit shutdown occurs.
3.3.2
1) In cooling mode, the indoor fan operates continuously.
The fan speed can be set to low, medium, high, turbo
and auto.
2) Auto fan action in cooling mode:
Product Features 3

Compressor Control
Indoor Fan Control
