Control Principle And Related Test Functions; Air Damper; Motor; Defrost Control Principle - Haier HFD647AS Service Manual

SERVICE MANUAL
Model: HFD647AS/HB21TSSAA
Chapter 5 Control principal and related test functions

5-1. Air Damper

(1) The refrig eration air damper is controlled with the fresh food storage te mperature sensor R
SNR.
(2) The air damper is closed from the beginning of defrosting until 15 minutes after the defrosting is
finished.
(3) Upon initial powering on or resetting of the control panel, the air damper conducts a
close-and-open cycle before acting according to the control conditions in item (1).
(4) The air damper will be forced to conduct an open-and-close cycle if it has been closed for 1 hour.
After that, its closing/opening will be controlled by RSNR.
(5) The air damper will automaticlly close when REF. door has been opend over 2 minutes.
5-2. Control Principle of the Fan motor
Control principal of the evaporator fan motor and fresh food damper.
1 . When a fresh food door is opened, the evaporator fan motor will operat e on high speed and the
damper will be full open. After 2 minutes with the door open, the damper will close but the evaporator
fan motor will operate according to the compressor function.
2. The evaporator fan motor will not operate if the freezer door is open ,even if the fresh door is open.
3. An error code alerting of a fan motor problem will appear (see error code section) if the motor
speed is below 300rpm or does not operate for longer than 30 seconds during the run cycle.
Condenser fan motor's controlling:
The motor works with compressor synchronous.condenser fan motor has a 12V's power supply
voltage while the rotate speed 1150RPM on normal. And high speed operation is 13.5v - 1300rpm.
5-3.Defrosting Control Principle of HB21TSSAA & HFD647* Refrigerator
Compressor
Defrost heater
turns on
turns off
FC fan turns off
Air Damper
Closes
Defrost is terminate when the sensor reaches +7℃
Defrost aborted after 120 minutes
Accumulative
compressor run time
7 hours
ED displayed on LCD paned as fault
Defrost heater
turns off
Failing to reach +7℃
Defrost Time is
about 30 minutes
Compressor Freezer Fan
turns on
turns on
7 minutes 5 minutes
Air Damper
opens
Back to Normal Run
3 minutes
20