Refrigerator Test Model; Fan Motor Control - Haier HB21T NN Service Manual

4. Refrigerator Test Model

TEST1：For testing the capability of cooling!
Hold the refrigerator temperature control button(A) and the freezer temperature control button(C)
3 seconds to enter into <PULL DOWN MODEL>, "T1T1" will show on the display screen and
force appliance to cool down immediately : during this time the compressor run normally, fan
motor run at a high speed and defrost heater is switched off .
TEST2：Under TEST1 MODE, hold the refrigerator temperature control button(A) and the
freezer temperature control button(C) a new 3 seconds to enter into <Force defrost MODEL>,
"T2T2" will show on the display screen and force appliance to defrost immediately: during this
time the compressor and fan motor are switching off, defrost heater is switching on. Power of the
defrost heater should be 250±15W here.
When temperature around defrost sensor above 7 degree, appliance will exit <Force defrost
MODEL> after heater working 1 minute!
When temperature around defrost sensor below 7 degree, heater will work continually until
reach 7 degree, appliance then exit <Force defrost MODEL>!
TEST3：Under TEST2 MODE, hold the refrigerator temperature control button(A) and the
freezer temperature control button(C) another 3 seconds to enter into <Assist heater MODEL>,
"T3T3" will show on the display screen and force heater of upright girder , heater of Freezer
horizontal girder, heater of water enter pipe for ice-maker and heater of fridge damper to switch
on, during this time the lamps in fridge and freezer room are all off and display screen . Power of
test should be 25±4W here.

5. Fan motor control

5.1 Freezer fan motor control
The freezer fan motor is controlled by main control panel according to these following
conditions. The speed of DC fan motor is adjusted adopting PWM mode. AC fan motor run
directly .
(1) Conditions for switch-on and switch-off (The fowling table is the control mode of DC Fan
motor. AC fan motor run under conditions for switch-on and stop under conditions for switch-off).
(2) When the fridge door is opened, freezer fan motor start running and fridge air escaper
open, then fridge air escaper will shut after 2 minutes.
(3) Freezer fan motor stop running when the freezer door is opened.
(4) How to judge the freezer fan motor is in LOCK condition: If the speed of fan motor no more
than 300RPM or stop running, and this condition last for more than 30 seconds, please check the
malfunction display of freezer fan motor. It will come back to normal display if motor in normal
condition, or else display freezer fan motor malfunction still.
5.2 Cooling fan motor control
(1) The cooling fan motor runs at the same time with the compressor.
(2) How to judge the cooling fan motor is in LOCK condition: If the speed of fan motor no more
than 300RPM or stop running, and this condition last for more than 30 seconds, please check the
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