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Electronic functional description – Amana Bottom Mount Refrigerator User Manual

Page 28

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RS1200001

28

November 1996

Electronic Functional Description

As the temperature decreases, resistance increases.
As the temperature increases, resistance decreases.
An open thermistor or thermistor circuit will result in
failure of refrigerator to cool. Shorted thermistor will
result in refrigerator to run 100 percent of time except
for defrost.

• Freezer temperature setting and thermistor value

will determine if compressor/condenser fan and
evaporator fan switches are open or closed.
Compressor/condenser fan switch must be open for
6 minutes before switch can close again
(compressor dwell time).

• Refrigerator temperature setting and thermistor

value will determine if fresh food fan switch is to be
open or closed.

• Cutout and cutin temperature values must be

reached and maintained for 15 seconds before
output state will change (digital delay).

Factory set freezer and refrigerator settings
Part # 12067101

Frozen

Food

Fresh

Food

Level

Cut-out

F° (C°) ±

1.5°

Cut-out

F° (C°) ±

1.5°

-10 (-23)

29 (-2)

9

-8 (-22)

31 (-0.6)

8

-6 (-21)

33 (-0.6)

7

-5 (-21)

34 (1)

6

-4 (-20)

35 (2)

5

-3 (-19)

36 (2)

4

-2 (-19)

37 (3)

3

0 (-18)

39 (4)

2

2 (-17)

41 (5)

1

-10 (-23)

----

Max Ref

----

29 (-2)

Max Frz

• Refrigerator or freezer control calibration can by

adjusted.

Adaptive Defrost Operation

• Defrost occurs after predetermined length of

compressor run hours. Compressor run time
between defrost changes or adapts, depending upon
recent history of defrost lengths (time it takes for
defrost terminator to open once defrost heater has
been turned on). Defrost terminator opens at 55°F
(13°C) and closes at 20°F (-7°C).

• Compressor run time between defrost (CRTD) will

be one of 3 values under normal operation: CRTD
(1), or CRTD (2) or CRTD (3) defined as 8, 12, and
16 hour lengths. If defrost length is low (DT-LO
defined as 21 minutes) indicating small frost load
CRTD for next defrost cycle is advanced to next
level. If defrost length is high (DI - HI defined as 24
minutes) indicating large frost load CRTD for next
defrost cycle is lowered to next level. Initial value at
power CRTD (0) is 4 hours.

• Vacation mode CRTD equals 96 hours. Vacation

mode CRTD is interrupted with door openings.
Defrost interval will revert back to the previous
interval before Vacation mode.

• Six minute dwell time occurs after defrost terminator

opens before compressor and condenser fan motor
will operate. Ten minute dwell time occurs after
defrost terminator opens before evaporator fan
motor will operate.

• Conventional defrost can be selected.

Power Up Condition

Nine temperature indicators will flash after refrigerator
is powered up. Refrigerator begins normal operation
immediately, except for 6 minute dwell before
energizing compressor circuit. Indicator lights will stop
flashing after Display On or Alarm Off pads are
pressed.

EEPROM Update in Control Memory

EEPROM is permanent programmable memory
device. Once function is changed and stored in
EEPROM, function is stored permanently and will not
be effected by power loss.

• After keyboard programming changes have been

made to refrigerator and freezer temperatures, entry
tone, and door audio alarm, status is permanently
stored in EEPROM after keyboard is disabled.

Accessing Program Mode
1.

Open refrigerator door.

2.

Press Display On pad.

3.

Press Vacation pad.

4.

Press following pads in sequence within
6 seconds: Max Ref, Max Frz, Max Ref, Max Frz.

5.

When access is granted, audio annunciator will
sound 3 times and control will be in program
Mode A.