Whirlpool KRFC704FSS - Theory of Operation - Refrigeration System

For Service Technician Use Only
DIAGNOSTICS
1-12
n
French-Door Boom Mount Refrigerator
Refrigeration System

The refrigeraon system compares actual compartment
temperatures to set-point temperatures. If the temperature is
too warm, the sealed system operates to cool the appropriate
compartment. Fans are run to move compartment air over the
evaporator, removing heat and cooling the compartment.

The refrigeraon system uses dual evaporators to control the
temperature of four temperature controlled zones located in two
separate compartments.
The compartments and temperature controlled zones are:

• Freezer Compartment (FC)
• Ice Box (IB)

• Refrigerator Compartment (RC)
• Temperature controlled drawer (pantry)

The refrigerator maintains the four temperature controlled zones
at the designated set-points. The temperature set-points for the
FC, RC, and Pantry are set using the Eyebrow UI. The IB set-point
temperature is xed at 14°F (-10°C).


Zone

C1
Freezer
Compartment
-5°F to 5°F
(-21°C to -15°C)
C1 Ice Box
5° F (-15°C) - Ice Making
14°F (-10°C) - Ice Bin Full
C2
Refrigerator
Compartment
33°F to 42°F
(0.5°C to 5.5°C)
C2 Pantry
Meats - 32°F (0°C)
Drinks - 35°F (2°C)
Deli / Cheese - 38°F (3°C)

The refrigerator compares the actual temperature to the
temperature zone set-point to determine when cooling is
necessary. Actual temperatures of the Pantry, RC, FC, and IB are
determined by a thermistor located in each temperature zone.

The refrigerator can only cool one of the two compartments
at a me. If both compartments are calling for cooling,
the refrigerator uses a cooling priority to determine which
compartment is cooled rst. Cooling priories are assigned by
comparing actual temperature to the temperature set-point.
The larger the deviaon above set-point, the higher the priority.
There are four cooling priories:
• 3 – High Priority,
• 2 – Medium Priority,
• 1 – Low Priority,
• 0 – Sased
C1 Priority = FC Priority + IB Priority
C2 Priority = RC Priority + Pantry Priority
The compartment with the higher priority will cool rst.
If a compartment is cooling and another compartment calls for
cooling, the rst compartment will connue to cool unl either
the temperature is sased, or for 15 minutes, whichever comes
rst. Aer this me, cooling switches to the other compartment.
If both compartments have High priority—for example, a warm
refrigerator just plugged in—the refrigerator will enter Pull-Down
Mode.
A
B
C
D
A. Ice Box
B. Refrigerator Compartment
C. Pantry
D. Freezer Compartment