Electrical Control Principle; Overview; Fridge Electric Air Damper Control; Fan Control - Haier HB21FSSAA Service Manual

SERVICE MANUAL
Model: HB21FSSAA, HB21FG*
Chapter 5 Electrical Control Principle

5-1. Overview

The refrigerator belongs to whole no frost air cooling design.
The fridge chamber temperature is controlled by the fridge sensor controlling the switch of the air damper.
The freezer chamber temperature is controlled by the freezer sensor controlling the operating of the
compressor.

5-2. Fridge electric air damper control

(1) The air damper is controlled with the fridge temperature 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 R SNR.
(5) The air damper will automaticlly close when REF. door has been opend over 2 minutes.
(6) When the fridge sensor failure, air damper will work according to fixed cycle: ON 10 minutes,
then OFF 15 minutes.
Operation can be used in check air damper: Press refrigerator temperature setting button for 3
seconds under lock status, then the fridge room is closed, and temperature and setting display board
go out, fridge air damper is closed.

5-3. Fan control

Control principal of the freezer fan motor:
1. When a fridge food door is opened, the freezer fan motor will operate at high speed and the damper
will be full open. After 2 minutes with the fridge door open, the damper will close, but the freezer fan
motor will operate according to the compressor function.
2. The freezer fan motor will not operate if the freezer door is open .
3. The freezer fan will not stop running if any one of the fridge chamber and freezer chamber can not
reach the setting temperatuer.
4. When the freezer sensor failure, freezer fan will work according to fixed cycle: ON 15 minutes, then
OFF 15 minutes.
Condenser cooling fan motor's controlling:
The cooling fan works with the compressor synchronously.
If the running speed of evaporator / Condenser fan motor is lower than 300RPM, or stop running, and
or longer than 30 seconds during the run cycle, the appliance will display error code E1/E2. It will come
back to normal display if fan motor resume normal condition, or else it keep display error code..
Issue 2010-12
Rev.
Ref1012S008V0
26