Auto Mode; Drying Mode; Forced Operation Function; Timer Function - Mars Comfort-Aire Century VCD-SA Series Service Manual

Service Manual - VCDxxSA
• The unit enters defrosting mode according to the
temperature value of T3 and T4 as well as the
compressor running time.
• In defrosting mode, the compressor continues to run,
the indoor and outdoor motor will cease operation,
the defrost light of the indoor unit will turn on, and
the " " symbol is displayed.
• If any one of the following conditions is satisfied,
defrosting ends and the machine switches to normal
heating mode:
• T3 rises above TCDE1.
• T3 maintained above TCDE2 for 80 seconds.
• Unit runs for 15 minutes consecutively in defrosting
mode.
• If T4 is lower than or equal to -22°C and compressor
running time is more than TIMING_DEFROST_TIME,
if any one of the following conditions is satisfied,
defrosting ends and the machine switches to normal
heating mode:
• Unit runs for 10 minutes consecutively in defrosting
mode.
• T3 rises above 10°C.
For some models:
• If any one of the following conditions is satisfied, the
unit enters defrosting mode
• If T3 or T4 is lower than -3°C for 30 seconds,Ts-T1
is lower than 5°C and compressor running time is
more than EE_TIME_DEFROST7.
• If T3 or T4 is lower than -3°C for 30 seconds and
compressor running time is more than EE_TIME_
DEFROST7+30.
• If any one of the following conditions is satisfied,
defrosting ends and the machine switches to normal
heating mode:
• T3 rises above TCDE1+4°C.
• T3 maintained above TCDE2+4°C for 80 seconds.
• Unit runs for 15 minutes consecutively in defrosting
mode.
3.4.5 Evaporator Coil Temperature Protection
When the evaporator temperature exceeds a preset
protection value, the compressor ceases operation.
3.5

Auto Mode

• This mode can be selected with the remote controller
and the temperature setting can be adjusted between
16°C~30°C.
• In auto mode, the machine selects cooling, heating, or
fan-only mode on the basis of ∆T (∆T =T1-TS).
∆T
∆T>2°C(3.6°F)
-3℃(-5.4°F)<∆T≤2°C(3.6°F) Fan-only
∆T≤-3°C(-5.4°F)
Heating*: In auto mode, cooling only models run the fan
• Indoor fan will run at auto fan speed.
• If the machine switches mode between heating and
cooling, the compressor will keep stopping for certain
time and then choose mode according to ∆T.
3.6

Drying Mode

• In drying mode, AC operates the same as auto fan in
cooling mode.
• All protections are activated and operate the same as
they do that in cooling mode.
• Low Room Temperature Protection
If the room temperature is lower than 10°C, the
compressor ceases operations and does not resume until
room temperature exceeds 12°C.
3.7

Forced Operation Function

Press the AUTO/COOL button, the AC will run as below
sequence:
• Forced cooling mode:
The compressor and outdoor fan continue to run and
the indoor fan runs at breeze speed. After running for 30
minutes, the AC will switch to auto mode with a preset
temperature of 24°C(76°F).
• Forced auto mode:
Forced auto mode operates the same as normal auto mode
with a preset temperature of 24°C(76°F).
• The unit exits forced operation when it receives the
following signals:
• Switch off
• Changes in:
3.8

Timer Function

• The timing range is 24 hours.
• Timer On. The machine turns on automatically at the
 Product Features 5
Running mode
Cooling
Heating*
Forced auto →Forced cooling →Off
• mode
• fan speed
• sleep mode
• Follow me
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