The information contained in this manual pertains to
Zero Zone 2- and 3-door self-contained freezers
used for frozen food or ice cream merchandising.
Zero Zone has made every effort to produce
refrigeration equipment of the highest quality using
state of the art components and modern
manufacturing techniques.
Read these instructions carefully and completely
before attempting to install Zero Zone equipment.
Refer to all National, State, and local electrical,
health and HVACR code requirements before
installation.
These display freezers are designed to operate in
an air-conditioned environment where the air
temperature is maintained at 75°F or lower and the
relative humidity does not exceed 55%.
Inspection
These display freezers were factory-tested,
inspected and properly packed to ensure delivery in
the best possible condition. This equipment should
be checked for damage immediately upon delivery,
both before and after. ALL CLAIMS FOR DAMAGES
MUST BE FILED WITH THE TRANSPORTATION
COMPANY – NOT WITH ZERO ZONE. The carrier
will supply necessary report and claim forms.
Location
The freezer must not be installed in the direct rays of
the sun or near a source of radiant heat. It must be
installed on a sound floor of sufficient strength and
must be level and plumb for proper operation.
A minimum 4” space between the back of the
freezer and the building wall or shelving must be
maintained for proper airflow.
INSTALLATION
Electrical
The freezer lights, fans, and door heaters operate
on 115 volt, 1 phase, 60 Hz. The compressor and
defrost heater operate on 208/230 volt, 1 phase, 60
Hz.
All internal wiring has been completed at the
factory. The 115-208/230 volt power connections
are made to the leads protruding from the left side
of the electrical box, which is located on the right
side of the compressor compartment.
A cord connection is optional on the 2-door case.
When a cord is supplied, a NEMA 14-20R four prong
20 amp twist lock receptacle must be provided in
your store. The cord length is approximately 6 feet.
A four-wire 115-208/230 volt single-phase circuit is
required for both case sizes. Wiring should be sized
according to the amperage rating stamped on the
serial plate. A standard 2-door case is rated at 20
amps. A standard 3-door case is rated at 25 amps.
Note: all wiring must comply with the National
Electrical Code and all local codes.
Start-up
Make sure the compressor floats free on the
mounting grommet. The case is shipped with the
valves back seated (open).
Energizing the electric circuit will start the case. On
cord-connected units, the on/off switch must be
switched on after the cord is connected. The on/off
switch is mounted on the electric box located in the
front of the case behind the grill. After the case is in
operation, set the Time Clock to the proper time of
day so that defrost will occur at the desired time.
To set the Time Clock, remove the front grill and
locate the display on the face of the electrical box.
Flip up the plastic bezel face of the display to reveal
four keypad buttons.
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1. Press and hold SET for 5 seconds. The display
will show CloC.
2. Press SET again to change the time of day.
3. Press up or down until the correct time-of-day
is displayed.
4. Press SET to accept the change.
5. Press the down arrow twice to exit the menu.
See page 8 of the ERC2 manual for more details.
Note: When the freezer is started from an ambient
condition, the lights and fans may not immediately
turn on. They will turn on and off until the coil
temperature reaches a stable 25°F or lower. The
limit control regulates the operation of the fans and
lights. Refer to defrosting section for complete
details.
USER INFORMATION
Cleaning
The freezer should be thoroughly cleaned before
start-up, and routinely thereafter to maintain a clean
appearance. Use mild detergent and warm water
(never an abrasive cleaner) to wipe the inside of the
freezer. Wash down all glass doors with a good
glass cleaner. The freezer will remain bright and
sparkling with just a few minutes of cleaning each
week.
Note: Do not use high-pressure water or steam
to clean the interior. Remove any debris to
prevent the drain tube from clogging.
Shelf Location (See Specifications)
The shelves are adjustable in ½ inch increments
and may be located in any position for best display
advantage due to the air discharge arrangement. It
is suggested that the uppermost shelf be placed 10
to 11 inches down from the ceiling and the
remaining shelves approximately 10 inches apart at
the front of the freezer.
Temperature Control
An electronic time clock is used to regulate
temperatures in the freezer. A temperature probe
located in the return air sends temperature
information to the control. The control is factory-set
to maintain a freezer air temperature of -8°F to 16°F. The control is mounted in the control panel
box located at the right front of the compressor
compartment.
To adjust the temperature, remove the front grill and
locate the display on the face of the electrical box.
Flip up the plastic bezel face of the display to reveal
four keypad buttons.
6. Press and hold SET for 5 seconds. The display
will show CloC.
7. Press the down arrow and the display will
show SEt.
8. Press up or down to go to the desired setpoint
temperature.
9. Press SET to accept the change.
10. Press the down arrow to exit the menu.
See page 8 of the ERC2 manual for more details.
Loading The Freezer
The freezer may be loaded with merchandise after it
has been operating for at least 12 hours with correct
case temperature and proper control operation.
While loading the shelves, leave at least 1-1/2”
between the top of the merchandise and the
shelf immediately above it so the customer can
reach to select the merchandise. This space also
helps in maintaining proper airflow in the freezer.
Light Switch
The light switch is located inside the freezer in the
right door opening. Always turn the lights off when
replacing lamps.
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DEFROSTING
General
Periodic defrosting to keep the coil free of excessive
frost for top efficiency is accomplished automatically
by the control system. A time clock is used to
defrost the freezer coil at predetermined times
during the day.
Defrost Time Clock
The defrost sequence of operation is as follows:
When the control system initiates a defrost cycle, the
fans, door heaters and compressor are turned off.
The defrost heater is energized and defrosting
begins. As the ice on the coil melts, the
temperature in the coil rises to the set point. When
the set point is reached, the defrost is terminated.
If the coil temperature fails to reach the termination
temperature but the fail-safe time has elapsed, the
control system will terminate the defrost.
In either case, normal freezer operation is resumed.
DEFROST FACTORY SET POINTS
NUMBER/DAY 2
TERMINATION 48 º F
FAIL SAFE 50 MIN.
DEFROST TIME 8 am & 8 pm
Adjustments can be made to the number of
defrosts, termination temperature or time, and time
of each defrost. See page 9 and 10 of the ERC
manual for instructions.
Limit Thermostat
Each freezer has a factory set limit thermostat to
regulate the operation of the evaporator fans, and
door heaters. The thermostat is built into the
electronic control.
BECAUSE OF THE LIMIT THERMOSTAT, THE
EVAPORATOR FANS AND DOOR HEATERS WILL
REMAIN OFF UNTIL THE COMPRESSOR IS OPERATING
AND THE COIL TEMPERATURE IS BROUGHT BELOW
THE THERMOSTAT CUT-IN SETTING (+25°F.).
When the freezer first operates (due to temperature
fluctuations), the fans may cycle off and on a few
times until coil temperature is below +25°F.
SERVICE
! CAUTION !
DISCONNECT POWER TO THE CASE BEFORE
SERVICING ELECTRICAL COMPONENTS.
Evaporator
The evaporator coil is located at the bottom rear of
the freezer under a two-piece metal cover. To
inspect the coil, remove the sheet metal screws
from the cover and back wall. The shorter cover on
the right side must be removed first.
Expansion Valve
A thermostatic expansion valve with pressure
limiting ZP charge, adjustable super-heat and
sensing bulb is mounted to the evaporator outlet.
Under certain conditions, it may be necessary to
adjust the super-heat setting for maximum coil
effectiveness. To adjust the expansion valve,
remove the right end coil cover from the top end of
the coil. Remove the cap from the valve. When
looking at the valve stem, turn it counterclockwise to
open the valve. Turn the valve stem clockwise to
close the valve. Measure the suction line
temperature at the expansion valve-sensing bulb
and compare it to the suction temperature
corresponding to the saturated pressure.
Turn the valve stem only ¼ turn at a time and allow
sufficient time for the valve to settle before making
any further adjustments. Replace the valve stem
cap after the valve super-heat has been adjusted.
BE CERTAIN THE VALVE STEM CAP IS WIPED DRY.
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Figure 1. Removing Lamp
4
Electric Defrost Element
The defrost element is located under the evaporator
coil. The electric wire leads are connected in the
electrical box located on the right side of the
compressor compartment. To remove the defrost
element, remove the coil covers. Take out the two
sheet metal screws in front of the heater tray. These
screws are located one on each end of the
evaporator coil. Then slide out the complete heater
pan assembly from under the coil and under the fan
housing. Slowly lift the heater pan assembly
between coil and fan housing, turning it on edge
while lifting.
Evaporator Fans
Air is circulated throughout the freezer with shaft up,
115-volt low temperature fan motors. These motors
must be operating at all times except during defrost.
To service the fan:
1. Disconnect all power.
2. Remove wire fan guard and the two mounting
bracket screws.
3. Unplug fan from fan power supply plug located
under fan housing.
Lights
High output 1500 milliamp
bulbs are standard with
these freezers. To ensure
maximum component life,
always replace with 1500
milliamp bulbs. Use
retainer clips and lamp
shields.
To change a light bulb, turn
off the light switch and
remove the retainer clip
located between the socket
and the end cap. Carefully lift the lamp up into the
spring-loaded lamp socket to allow the bulb to be
removed from the bottom socket. (See Figure 1.)
Remove the end caps and lamp shield.
Alternate lighting – T8
These systems use a lens to direct light output
evenly across the shelves. The bulb used is an
Osram FO32W/41K (4ft). The lens must be removed
to access the bulb. With the lens removed, reach
into the fixture and remove the mylar warning cover.
Remove the bulb/socket assembly by carefully
pulling away from the top and bottom retaining
clips. Move the foam center seals away from the
electrical connectors. Disconnect the electrical
connectors on the top and bottom sockets by
depressing the locking tab and pulling away from
the socket. Detailed information is contained in the
door instruction booklet.
Compressor Access Panel (Grill)
The compressor access panel (grill) is located at the
front bottom of the freezer. It can be taken off by
removing the two screws at the bottom ends of the
panel. Drop the panel down and pull the bottom of
the grill outward. The panel must be removed
before any service work can be done to the
compressor, electronic control system or
condensate drain pan heater.
Compressor
A 208/230v, 1 phase, 60 Hz, R404A/R507 (prior to
1/95 R502) compressor is mounted in the
compressor compartment located below the
freezer. The condensing unit is equipped with a
liquid receiver, and suction service valves for the
refrigeration technician.
R404A is the standard refrigerant. Check your
nameplate to determine if R507 was supplied as a
special order.
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Light Ballast
The 3-door freezer has two (2) two-lamp ballasts.
They are located in the galvanized electric box on
the right side of the compressor compartment.
The 2-door freezer has one (1) three-lamp ballast. It
is located in the galvanized electric box located on
the right side of the compressor compartment.
If the case is equipped with T-8 lighting, the ballasts
are mounted in the door frame mullions.
Electrical Components
To remove the electric box cover, remove the 4
sheet metal screws from the face of the electric box.
The cover can then be removed for component
inspection or replacement.
The ERC-2 display is attached to the box cover,
connecting the box to the cover. Slowly remove
cover to prevent damage to cable or connector
sockets.
Refrigeration Components
Whenever refrigeration components have been
replaced, the low side should be pressurized and
the connections checked for leaks. Evacuate the
low side to remove moisture and noncondensables that may have been introduced
during the service process. After leak check and
evacuation, all of the service valves should be
opened to put the system into operation. A certified
refrigerant technician must do this work.
Condensate Drain Pan Heater
To replace the pan heater, disconnect the power
supply to case. Remove the electrical box access
panel. Heater wire connections are on the terminal
block mounted in the electrical box.
PREVENTIVE MAINTENANCE
1. Clean condenser fins at least once every month,
more often if freezer is in a dusty location.
2. Keep floor drain pan and drain tube clear of
debris.