IV. INTENDED USE
IV. a - OVERVIEW:
The Air Curtain Refrigerator is specifically
designed to hold 45°F or lower temperature
with the door(s) open for a minimum of 30
minutes, or longer dependent upon application
and operating conditions (room temp, humidity,
surrounding air exchanges, and voltage).
When the door of the unit is closed, it operates
as a force air refrigerator with a highly efficient
refrigeration system that provides faster “pull
down” and “recovery” times than standard
refrigerators. When the door is opened, a
series of blower fans create a “wall” of air and
areas of pressure, localizing a unique pattern
of air from both the left and right side walls,
as well as from the top. This movement across
the cabinet opening keeps the cold air in
and the warm air out of the food zone for
90 minutes. This AIR CURTAIN seals itself
around objects and is ideal for hospital and
nursing home tray line / assembly line kitchen
operations, flight kitchens, cafeterias, fast food
and QSR applications. For best results, the
air curtain was designed for “low profile”
food products typical of these applications.
IV. b - TYPICAL OPERATING PARAMETERS:
The “curtain” is capable of maintaining 45°F
temperature or below for 45 to 90 minutes
based at 75°F / 45% RH / 120V 20 amp
dedicated circuit. HOWEVER, actual time your
unit will run in this temperature zone depends
on many factors, such as: room ambient
temperature, humidity levels, air disruption
(such as a hood, vent, or air return), amount of
time unit was allowed to precondition the
food(s), food temperatures when placed into
the unit, type of food packaging, and profile of
foods. It should also be noted that there is a
lag time between the “ambient air” temperature
in the cabinet and that of the actual product
temperature. The food temperature differential
can be 10°F - 20°F cooler than the temperature
indicated by the temperature display.
IV. c - SUGGESTED PAN SIZING:
Traulsen has designed this unit to operate
with 18" x 26" trays. Ten (10) pair of removable
tray slides are provided at a fixed 4-1/2"
specific spacing to assure proper air-flow
and maximum performance.
IV. d - PRODUCT UNLOADING:
When unloading product from the Air Curtain
refrigerator, it is recommend that this be done
from the top down. Empty trays can be
removed or left in the unit after unloading
their contents and will not effect the overall
performance of the unit.
V. PRODUCT FEATURES
V. a - CASTERS:
6” high polyurethane casters are supplied
standard for Air-Curtain models. They are
attached to 10-gauge stainless steel corner
plate reinforcements/stress pads. These are
shipped already installed on the unit for
immediate use.
V. b - GRIPS & HANDLES:
For easy mobility, stainless steel recessed
hand grips are provided on the left and right
sides. In addition, a 1” welded tubular push/pull
handle is attached to the rear of the cabinet.
V. c - ELECTRONIC CONTROL:
All Traulsen Air Curtain units are supplied
a microprocessor controller.
V. d - ON DEMAND DEFROST:
Traulsen Air-Curtain models are supplied with
a momentary defrost cycle. It is located on the
front control (see figure 1), and by depressing
the switch, the unit will self defrost (maximum
of 15 minutes). During a defrost cycle, the
indicator light will illuminate above the switch
and the controller display will show “Def” and
momentarily disable the compressor, the coil
and the fans. This “On-Demand Defrost” feature
allows proper defrosting of the accumulated
condensation and ice build-up on the coil.
Defrosting is needed to assure maximum
efficiency and heat exchange of the coil,
assuring maximum performance. After the
defrost cycle ends, the unit will wait
60 seconds before the compressor and or the
fans will return to normal operation, achieving
the best restart performance and cooling
temperatures. It is possible that the unit will
self-initiate a defrost if excessive ice is on coil.
NOTE: If the coil is not defrosted, temperatures
will rise and reduced performance will be
noticeable. Check water pan for a higher water
level which indicates a successful defrost of
the coil. Certain conditions may require 3
repeated sequential defrosts.
If the unit is in a defrost cycle, it can be
cancelled by pushing the defrost button.
This will force the unit out of the defrost cycle.
The unit will wait 60 seconds before the
compressor and or the fans will return to
normal operation, achieving the best restart
performance and cooling temperatures.
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V. PRODUCT FEATURES (cont’d)
V. e - CONDENSATE EVAPORATOR:
During the “On-Demand Defrost” cycle or the
“Off Cycle” of the compressor, the evaporator
coil will defrost. The condensate from the
evaporator coil flows from the top of the unit
down a drain in the back to a condensate pan.
Vapor escapes through the back grill. The
vapor can sometimes be visible and should be
considered a normal operating condition.
Proper attention should be given to defrosting
your unit. Every “event” or time the unit is used
with the door open, the coil will build-up ice.
This reduces the effectiveness of the overall
operation of the unit.
V. f - TRAY SLIDES:
Ten (10) pairs of removable tray slides are
provided standard at 4-1/2" spacing. Each tray
slide can accommodate one (1) 18" x 26" pan /
tray.
V. g - WRAP-AROUND PERIMETER BUMPERS:
As the Air-Curtain refrigerator was designed
to be mobile, a full extension perimeter rubber
bumper guard is included to protect the unit
as well as surrounding walls and doors during
movement.
VI. ELECTRONIC CONTROLLER
VI. a - CONTROL OVERVIEW:
The Traulsen Air Curtain models are supplied
standard with an easy to use microprocessor
control. It features several important user
functions, greatly enhancing the overall utility
of the cabinet. The Traulsen RAC-37 is the only
two-stage (two temperature settings) Air
Curtain currently available on the market.
This feature allows the unit to be placed into
service at either “Standard Temp” or lower
“Colder Temp” settings.
VI. b - CONTROL FEATURE - ON/OFF:
This button has two uses: The first is to turn
the unit ON and OFF. The second allows for the
temperature display to be changed to indicate
either degrees (F) Fahrenheit or degrees (C)
Celsius. To change between temperature
scales; While unit is OFF, press and hold
the ON/OFF button for five (5) seconds. The
refrigerator will start and then the display will
switch from “dgF” to “dgC”. Repeat this step
to change the temperature scale again.
VI. c - CONTROL FEATURE - “ON” LIGHT:
When illuminated the ON light indicates that
the power is ON.
VI. d - CONTROL FEATURE - “CYCLE” LIGHT:
When illuminated the CYCLE light indicates
that the cabinet is cooling down to the desired
SET-POINT temperature. When cooling
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elements are activated, this light will remain
illuminated until the cabinet has reached the
SET-POINT temperature, and will go OFF at
that time.
VI. e - TEMP RECALL:
This feature displays either the actual internal
cabinet air temperature (default), or the desired
“Set-Point” temperature (alternate).
ACTUAL: The factory default setting shows
the actual (A) internal cabinet temperature and
acts as a digital thermometer. A momentary
touch of the TEMP RECALL button will recall
the original temperature setting. The display
will then automatically return the displaying
the actual internal cabinet temperature.
SET-POINT: To display the set-point (S)
temperature instead of the actual internal
cabinet temperature. The display will indicate
the set-point temperature until such time that
the temperature is approximately 5°F +/-
away from the set-point setting for more
than 5 minutes, at which time the display will
indicate actual temperature. Once the internal
temperature return to set-point, the controller
resumes to show set-point values.
To switch from one of these display functions
to the other, press and hold the TEMP RECALL
button for five (5) seconds. The display will
flash either “S” (SET) or “A” (ACTUAL) to
indicate which mode is active. To switch
back again, repeat this step holding the
TEMP RECALL button for five (5) seconds.
VII. OPEN DOOR:
During open door operation a sensor knows the
door is open, display will show “OPEn”. An internal
countdown timer will start, factory default will
allow unit open door operation for a maximum of
90 minutes. During the 90-minute open door
operation the cooling system will remain on.
If door is open longer than 90 minutes an open door
alarm will be activated. Display will flash “OPEn”
and beep three times every ten seconds.
To terminate the open door alarm, the door must
be closed and remain closed for 30 minutes.
(See page i).
DISPLAY UNDER NORMAL OPERATION:
• Unit will display internal and/or set point
temperature (see pg. 4, VI)
• A door sensor knows the door is open. When
operating with door open the display will show
“OPEn”.
• After a 90-minute open door operation, unit will
have a “5 min” (minute) countdown display prior
to terminating operation. (see page i).
• Unit will perform a defrost operation, after a door
open secession, the display will show “Def”. This
ensures optimum open door performance during
the next door open secession. Door must remain
closed until defrost cycle is complete,
approximately 30 minutes.
