Abbreviation; Fan Mode; Cooling Mode - Carrier 42QFD048D8S Service Manual

3.2

Abbreviation

Unit element abbreviations
Abbreviation Element
T1 Indoor room temperature
T2 Coil temperature of evaporator
T3 Coil temperature of condenser
T4 Outdoor ambient temperature
TS Set temperature
TP Compressor discharge temperature
In this manual, such as CDIFTEMP, HDIFTEMP2, TCE1,
TCE2...etc., they are well-setting parameter of EEPROM.
3.3

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 high, low, or auto.
• The louver operations are identical to those in cooling
mode.
• Auto fan: In fan-only mode, AC operates the same as
auto fan in cooling mode with the temperature set at
24°C.
3.4

Cooling Mode

3.4.1 Compressor Control
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.
• 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)
Note: CDIFTEMP is EEPROM setting parameter. It is 2°C
usually.
2) When the compressor runs continuously for more than
120 minutes.
• If the following conditions are satisfied, the
compressor ceases operation.
• When calculated frequency(fb) is less than minimum
• When protective time is more than or equal to ten
• When T1 is lower than or equal to (Tsc-CDIFTEMP).
Note: CDIFTEMP is EEPROM setting parameter. It is 2°C
usually.
3) If one of the following conditions is satisfied, not judge
protective time.
• Compressor running frequency is more than test
• When compressor running frequency is equal to
• Change setting temperature.
• Turbo function on/off
• Various frequency limit shutdown occurs.
3.4.2
• In cooling mode, the indoor fan operates continuously.
The fan speed can be set to high, (medium),low, or
auto.
• Auto fan in cooling mode:
3.4.3
Case 1:
• The outdoor unit will be run at different fan speed
according to T4 and compressor frequency.
• For different outdoor units, the fan speeds are
different.
Case 2:
• The outdoor unit will be run at different fan speed
according to T4.
• For different outdoor units, the fan speeds are
different.
 Product Features
limit frequency(FminC).
minutes.
frequency.
test frequency, T4 is higher than 15°C or T4 sensor
fault
Indoor Fan Control
Outdoor Fan Control
4 