Traulsen RET232NUT-FHS, RET232NUT-HHS Refrigerator User Manual


 
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VI. a - INTRODUCTION/OVERVIEW:
The Traulsen Even Thaw is designed to be used as a
thawing cabinet. While it may be utilized in a
refrigeration mode, that is not its intended use. Its
function is to hold the cabinet temperature in the
range from 38 to 40 degrees to thaw product within
the food-safe temperature zone. It has not been
configured to hold colder product temperatures in the
35 to 38 deg F range as desired by some customers.
Frozen product placed into the unit will pull the
cabinet temperature below the heater set point (37
deg.) and the unit will begin to function in the thaw
mode. This prompts the refrigeration system to turn
OFF, and the heaters to turn ON. The fans remain ON,
circulating this cold air around the product, allowing
for rapid thawing. When cabinet air temperature
reaches the upper set point (38 deg. although the
product is actually much colder), the heaters turn OFF.
As the cabinet temperature reaches the heater set
point, the heat will be cycled off while the internally
generated heat from the circulation fans continues to
add heat to the cabinet. If sufficient cold capacity or
possibly other frozen product is added to the unit and
subsequently lowers the cabinet temperature more
than 1 degree below the heater set point, the heat will
again turn on to thaw the product.
If the cold capacity of the product no longer sufficiently
pulls down the cabinet temperature below the heater
set point, the cabinet temperature will slowly rise to
attain the evaporator coil cut-in set point (41 deg.) and
energize the refrigeration system. The unit will remain
in the refrigeration mode until the cabinet
temperature pulls down to the compressor cut-out set
point (38 deg.). The unit will continue to operate and
cycle in the refrigeration mode.
The units incorporate a mode switch located behind
the louvered panel. Switching to the Refrigeration
mode (switch OFF) will turn off two internal blower fans
and will reduce the Thaw mode (switch ON)
performance. Subsequently, switching to the Thaw
mode will have reduced refrigeration performance.
The controller has been preset at the factory and
should not require any adjustments. Traulsen
engineering EXPECTS no changes be made to any set
points or parameter settings without discussing the
situation and obtaining approval to do so. Modifying
the default set points could disrupt the operation/
functional programming algorithm and result in erratic
unit operation.
VII. GENERAL USE, OPERATION & SERVICE SUMMARY
VI. b - LOADING GUIDELINES:
The Even-Thaw model can accommodate any size
partial load, or up to (28) 18 x 26 pans of product (for
example approximately 672 lbs. of chicken). Use of alu-
minum pans is highly recommended. Product should be
placed on pans in one layer only to allow for proper air-
flow. With a full load thaw time will be between 22 & 24
hours. Overloading and/or double wrapping product will
extend thaw times.
VI. c - LED LIGHTS:
The controller has two LED lights that can be useful. One
is marked H, which will be lit when in the Refrigeration
mode. The other is marked G and will be lit during the
Thaw mode. When the H LED is lit the controller will
supply line voltage to the compressor relay coil closing
the N/O contacts in turn supplying line voltage to the
condensing unit. When the G LED is lit the controller
will supply between 3 to 30 VDC to the solid-state relay
coil closing the N/O contacts in turn supplying line
voltage to the mullion heater.
VI. d - CALL SERVICE LIGHT:
If lit, this indicates that one of the two temperature
sensors is either OPEN or SHORTED. To check the
resistance value per given temperature is correct place
the sensor in an ice bath (32 deg.). The resistance value
should be 100 ohms + 2%. There is a cabinet sensor
inside the heater/blower chamber and another sensor in
the evaporator coil.