![background image](http://html1.mh-extra.com/html/carrier/38qus012d8s/38qus012d8s_service-manual_2560795098.webp)
Electrical Control Function
Electrical Control System
96
1.
Electrical Control Function
1.1 Abbreviation
T1: Indoor room temperature
T2: Middle indoor heat exchanger coil temperature
T2B: Indoor heat exchanger exhaust coil temperature
T3: Outdoor heat exchanger pipe temperature
T4: Outdoor ambient temperature
T5: Compressor discharge temperature
1.2 Main Protection
1.2.1 Compressor Restart Delay
1.2.2 Temperature Protection of Compressor Discharge
When the discharge temperature of compressor rises, the running frequency is limited according to the
following rules:
18K 24~60K
T5
Compressor off
Frequency limit1
F
E
D
C
Frequencies increase slowly
B
Normal
A
Frequency holding
Frequency limit2
T5
Compressor off
Frequency limit
Normal
Frequency holding
1.2.3 Indoor Fan Delayed Open Function
When the unit starts up, the louver is immediately active . The indoor fan opens 7 seconds later.
If the unit runs in heating mode, the indoor fan is also regulated by the anti-cold wind function.
1.2.4 Fan Speed Malfunction
For A6 Duct:
If a fault occurs on the air volume regulator or the regulator enters protection mode, it sends the error
message CF and an instruction to reduce fan speed to the master. The message and the instruction can be
inquired with the remote controller or the wired controller. (Fault and protection information are displayed for
one minute). After a fault occurs, the master unit shows the error code E3 and the fault count for one minute.
If the fault occurs three times, then the fan is unable to resolve the problem independently. External
shutdown by a remote controller, wired controller, or central controller must be used to clear the fan fault and
fault count. The fan runs normally for 5 minutes while clearing fault count.
0
:
No malfunction
1
:
P0 Overcurrent
2
:
Overpressure
3
:
Overload
4
:
Over speed
5
:
Startup malfunction
Summary of Contents for 38QUS012D8S
Page 1: ...Contents i Energy Related Products SUPER DC INVERTER SERIES Service Manual...
Page 13: ...Service Space Indoor Units 11 3 Service Space 1000mm 1000mm 1000mm 1000m m Chart 3...
Page 16: ...Air Velocity Distributions Reference Data Indoor Units 14 30 42K Cooling Heating...
Page 17: ...Air Velocity Distributions Reference Data Indoor Units 15 48 55K Cooling Heating...
Page 22: ...Field Wiring Indoor Units 20 10 Field Wiring 42QTD018R8S 42QTD024R8S 42QTD036R8S...
Page 23: ...Field Wiring Indoor Units 21 42QTD048R8S 42QTD060R8S...
Page 29: ...Features Indoor Units 27...
Page 46: ...Service Space Indoor Units 44 3 Service Space...
Page 61: ...Wiring Diagrams Outdoor Units 59 3 Wiring Diagrams 38QUS018R8S...
Page 62: ...Wiring Diagrams Outdoor Units 60 38QUS024R8S...
Page 63: ...Wiring Diagrams Outdoor Units 61 38QUS036R8S...
Page 64: ...Wiring Diagrams Outdoor Units 62 38QUS036R8T...
Page 65: ...Wiring Diagrams Outdoor Units 63 38QUS048R8T 38QUS060R8T...
Page 87: ...Refrigerant pipe installation Installation 85...