Auto Mode; Forced Operation Function; Timer Function; Sleep Mode Function - Carrier 38GRQB12-3 Service Manual

For 9K, 12K models:
on
Compressor
off
on
4-way valve
off
on
Outdoor fan
off
on
Indoor fan
off
10s
Indoor fan breeze(10s)
xx
(no longer than 10 min.)
xx=60s for 9k & 12k models
For 18K, 26K models:
on
Compressor
off
on
4-way valve
off
on
Outdoor fan
off
on
Indoor fan
off
10s
Indoor fan breeze(10s)
xx
Defrost Cycle
(no longer than 10 min.)
XX=60 for 18k model, XX=90 for 26K, 30K models

AUTO MODE

In the Auto mode, the temperature can be set to values between
62~86F (17~30 ). In this mode, the machine will choose
cooling, heating or fan- only mode according to ΔT.
NOTE: ΔT =T1- Ts, where T1 represents the indoor room
temperature and Ts represents the set temperature.
ΔT=T1- Ts
ΔT＞33F
- 1<ΔT≤33F
ΔT≤- 30F
Indoor fan will run at an automatic fan speed for each running mode. The
louver will also operate depending in relevant mode taking place.
If the machine switches mode between heating and cooling, the
compressor stops for 15 minutes and then chooses a mode
according to ΔT.
If a new set temperature is commanded, the system chooses a
running mode according to ΔT.
10s
30s
Defrost Cycle
10s
30s
Running mode
Cooling
Fan- only
Heating

FORCED OPERATION FUNCTION

When the machine is off, pressing the manual button carries the
machine to forced auto mode. Press the button once again, within
5 seconds, the machine turns to forced cooling mode. In forced
auto, forced cooling or any other operation mode, press the
manual button to turn the machine off. When in this mode, all
general protections and remote control functions are available.
Forced cooling mode:
The compressor runs at F2 frequency and indoor fan runs as
breeze. After running for 30 minutes, the machine turns to auto
mode with a 75_F (24_C) set temperature.
Forced auto mode:
The action of forced auto mode is the same as normal auto mode
with a 75_F (24_C) set temperature.

TIMER FUNCTION

Timing range is 24 hours.
The timer function will not change the system's current operation
mode. The setting time is relative time.
Timer on
The machine turns on automatically when reaching the set time.
Timer off
The machine turns off automatically when reaching the setting time.
Timer on/off
The machine turns on automatically when reaching the set "on" time,
and then turn off automatically when reaching the set "off" time.

SLEEP MODE FUNCTION

Operation time in sleep mode is 7 hours. After 7 hours the system
turns off. Operation process in sleep mode is as follow:
When in cooling mode, the set temperature rises 1.8_F (1_C) (up
to a maximum 86_F (30_C)) every one hour. Two hours later the
set temperature stops rising and indoor fan is fixed at low speed.
Set point
° °C
2.0 F(-16.7
°
2.0 ° F(-16.7 ° C)
1
Fig. 23 – Sleep Mode - Cooling
When in heating mode, the set temperature decreases 2.0_F (- 16.7_C)
(down to a minimum 62_F (17_C)) every one hour. Two hours later
the set temperature stops rising and indoor fan is fixed at low speed.
NOTE: Anti-cold wind function has the priority.
Set point
2.0 ° F(-16.7 °C
°
2.0 ° F(-16.7 ° C)
1
Fig. 24 – Sleep Mode - Heating
When the user uses timer off function in sleep mode (or sleep
function in timer off mode), if the timing is less than 7 hours, sleep
function will be cancelled when reaching the setting time. If the
timing is more than 7 hours, the machine will not stop until it
reaches the set time in sleep mode.
17
)
2 Time (hour)
)
2 Time (hour)