Hussmann USL-2 Quick guide

January 2006
HUSSMANN - GLOVERSVILLE
INSTALLATION & SERVICE
INSTRUCTIONS
FOR
USL LOW TEMPERATURE
Solid Door Reach-In
for
Ice Cream and Frozen Foods
P/N OII – USL
January 2006
First Call for help (US and Canada):
1-800-922-1919
Soporte Tècnico y Asistencia (Mèxico):
01-800-522-1900
For a Service Network Locator and other
Information visit us at
www.hussmann.com
select Worldwide Locations

Page 1
TABLE OF CONTENTS
Page
Introduction, Inspection, Location, and Clearance 2
Installation and Start-Up 2
Skid, Leg Installation, and Top Decorative Panel Removal 2
CabinetDrain 3
Shelves 3
Air Distribution and Rear Flue Spacer 3
Electrical Connections 3
Serial Plate Information 3
Startupprocedure 4
Specifications, Dimensions, Electrical and BTU Capacities 4
General Upkeep, Care and Cleaning Routine Maintenance 4
Power Switches, Temperature Control 5
Thermometer, Electrical Enclosure 5
DefrostTimeClock 6
Defrost Heater Thermostat and Replacement 6
Lighting 7
Frame Heaters and Replacement 7
Expansion Valve Adjustment 7
Refrigeration, Leak Testing, and Evacuation 7 – 8
Operational Data, Compressor and Receiver 8
Crankcase Pressure Regulator 9
Trouble Shooting Charts 10 – 12
Electrical Components List 12
Warranty and Parts Information 12
Ordering Replacement Parts, and Compressor Replacement 12 – 13

Page 2
INTRODUCTION -
Hussmann USL models are self-
contained, low temperature, vertical solid
door reach-ins for the storage of ice cream
and frozen foods. Design features include
automatic defrost, efficient foamed in place
non-CFC insulation, and balanced refrigera-
tion systems for energy saving performance.
INSPECTION –
Upon receipt of the cabinet, carefully
examine the crating for damage. If the crate
is damaged, make a note on the delivery
ticket before signing. Carefully remove ship-
ping crate and examine cabinet for
“concealed damage. If damage is found, con-
tact the delivery carrier immediately and
have his agent prepare an inspection report
for the purpose of filing a claim. THIS IS
YOUR RESPONSIBILITY.
LOCATION –
The USL low temperature, storage,
self contained reach-ins are designed for
back room storage applications of ice cream
and frozen food products. Location where
drafts from air conditioning grille, fans and
open doors that would blow into the case
should be avoided.
CLEARANCE –
Because the condensing unit is located
at the top of the cabinet, at least 12 inches of
clearance should be allowed at the rear of the
cabinet and at the top of the case. This clear-
ance is necessary to provide free air move-
ment to and from the condenser for maxi-
mum operating efficiency.
INSTALLATION and START-UP –
SKID –
The skid should be left on the cabinet
until it is near the final location. The skid pro-
vides protection for both the case and floor.
The skid is removed by raising one end of the
case approximately six inches. BLOCK SE-
CURELY and remove the two skid bolts on the
raised end. This procedure is repeated on the
opposite end. When the skid bolts are re-
moved, the case may be slid off the skid.
LEG INSTALLATION –
After the case is near its final location
and the skid has been removed, the NSF ap-
proved legs should be installed. The legs are
packaged inside the cabinet. To install the
legs, replace the tape and door blocks. Raise
one end of the cabinet approximately 8 inches,
BLOCK SECURELY, and install two legs.
The leg mounting plates are factory installed
and contain a 1/2 x 13 tapped hole to match
with the leg assembly. The procedure is re-
peated on the opposite end. With the cabinet
legs installed, the cabinet should be positioned
in its final location and leveled.
The cabinet is leveled by turning the
bottom section of each leg. The self closing
doors require the cabinet to be properly lev-
eled. End to end leveling will make the doors
close with uniform speed and tightness. A
slight pitch from front to rear is desirable.
THE CABINET BACK SHOULD NEVER BE
HIGHER THAN THE FRONT.
TOP DECORATIVE PANEL REMOVAL –
The top decorative panel is removed by
sliding the panel up into the upper aluminum

Page 3
trim and pulling it forward until it clears the
bottom aluminum trim.
CABINET DRAIN –
A vinyl drain tube is provided for con-
nection to the condensate pan which is
mounted to the bottom of the cabinet. The
drain must be trapped to guard against the
drain line freezing, to prevent warm air from
going up into the back of the case, and for
good sanitation practice. A copper tube trap
is supplied for this purpose.
The condensate pan is electrically
heated. A separate 115 volt supply with a
ground rated at 10 amps should be provided
for this heater. The heater is supplied with a
115 volt supply cord with a grounding prong.
DO NOT REMOVE the grounding prong un-
der any circumstances.
The cabinet power switch does not
shut off the power to this pan. If the heater in
the pan should need replacing, be sure to dis-
connect the power source to the pan.
SHELVES –
Each cabinet is provided with 3 canti-
lever shelves per door that are adjustable on 1
inch increments & tiltable. Each cabinet also
has one bottom shelf per door. These shelves
have one inch legs to allow proper air flow in
the cabinet. Behind the shelves are wire flue
spacers which also allow for proper air flow.
All shelves and flue spacers are white, epoxy
coated for durability and ease of cleaning.
Care should be taken when loading the
shelves with product. Product on the highest
level of shelves, should not touch the evapora-
tor drain pan. This pan gets warm during the
defrost cycle, and some melting of the product
may occur if it is touching the pan/
AIR DISTRIBUTION and REAR
FLUE SPACER
-
Air is drawn through the evaporator
from front to rear and is discharged down the
back wall, returning up the face of the door to
the return air grill. NOTE: Rear wire grid
must be in place as this forms a discharge air
flue at the back of the cabinet
ELECTRICAL CONNECTIONS –
The USL-2 is supplied with a power
supply cord with a grounding prong. Do not
remove the grounding prong under any cir-
cumstances.
It is very important for safety to you
and your customers to have the cabinet prop-
erly grounded. The electrical installation
should be done by a qualified electrician in
accordance with the National Electrical Code
and/or local codes.
Note: Connecting this unit to
any electrical supply other
than specified on the serial
plate will void the warranty
and may result in serious
damage to the case. The cabi-
net should be supplied with its
own service.
SERIAL PLATE INFORMATION –
The serial plate is located in the upper
left hand corner of the case interior. It has all
the pertinent information needed for proper
electrical installation. The serial plate should
not be removed for any reason.

Page 4
START UP PROCEDURE –
1. After the wiring has been completed, set the
defrost timer for the correct time of day,
making sure the defrost pins are secure in
the face of the clock. USL cabinets are fac-
tory set for 1 defrost period in 24 hours. (12
a.m.)
2. Cut the band holding the compressor in
place during shipping.
3. Check the cabinet thoroughly for loose nuts
and bolts and electrical connections. In-
spect the refrigeration lines for any visible
damage or chafing.
4. Replace the electrical box cover.
5. Start the cabinet and allow to pull down to
operating temperature before loading.
SPECIFICATIONS –
DIMENSIONS –
Cu.
Ft. Exterior
Model Cap Drs L W+ H
USL-2 43.7 2 52” 34 1/4” 84 1/4”
Interior
47 13/16” 25 11/16” 62 3/4”
+ Exclusive of Door Handles
ELECTRICAL –
Unit
H.P. Hz/Ph Volts
USL-2 3/4 60/1 115
Run Fuse Ship
Amps Size Wt.
USL-2 15.0 20 amp 875
BTU CAPACITIES –
RatingTempsºF
BTU/HR Evap Cond. Amb
USL-2 2280 -20 110 90
During June ‘95, R404A refrigerant was
phased into use on the USL-2. The refriger-
ant charge is 46 oz. of R404A.
GENERAL UPKEEP
CARE and CLEANING –
To insure good sanitation, appear-
ance, and minimum maintenance, the cabinet
should be cleaned and washed regularly as
use demands. Clean with mild detergent and
warm water. DO NOT USE AN ABRASIVE
CLEANER OR STEEL WOOL AS THEY
WILL MAR THE FINISH.
ROUTINE MAINTENANCE –
Under normal conditions, after the
cabinet is installed and running, very little
maintenance should be required. However,
the following list of housekeeping practices
will assure trouble-free operation.
1. Check operation of condenser fan motors.
Fan blades must turn freely.
2. Check drain pan and heater to prevent
accidental overflow.
3. Make sure doors are closing properly and
that the gaskets seal.
4. Make sure all evaporator fan motors are
running. These can be seen through grill
inside cabinet.

Page 5
5. Clean the cabinet with a mild detergent.
This will insure good sanitation, and mini-
mize maintenance. Never use an abrasive
as this could mar the finish.
OPERATION and MAINTENANCE
POWER SWITCHES –
The power switch is located at the
electrical box which is behind the top decora-
tive panel. The switch will shut off all power.
TEMPERATURE CONTROL –
The temperature control is located in
the electrical box on the top of the case. The
temperature control does not have an ‘OFF’
position. Adjustments may be made by the use
of a screwdriver in the slot provided in the
face of the control. Turning it clockwise will
give warmer temperatures while counter-
clockwise will give colder temperatures. There
is also an adjustable temperature differential
( the difference between the cut-in temperature
and the cut-out temperature) located next to
the dial face.
The control has a range of –30ºF to
+50ºF with a differential of 5º to 20º. It is fac-
tory set for approximately –15ºF with an 8º
differential. The temperature should be
checked with a thermometer other than the
case thermometer after it is running to insure
that the case is running at the proper
temperature for the product.
THERMOMETER –
The thermometer is located in the
center of the top header. The thermometer
will probably need resetting to reflect the
proper case temperature. Using a separate
thermometer located on a shelf in the case,
compare this temperature to that on the case
thermometer. If the case thermometer needs to
be adjusted, remove the clear protective cover
by popping it off with a small screwdriver and
turning the small adjustment screw on the face
of the thermometer.
The thermometer is used to indicate
proper operating temperatures. For the USL
the proper operating temperature is –10ºF
to –15ºF.
The thermometer will also warm up
rather rapidly when the case door is held open
for a time such as when the case is being re-
stocked or a shopper is making a decision on a
product. After the door is closed it will take
some time for the thermometer to pull back
down to the case temperature.
The thermometer can be replaced by re-
moving the three screws securing it to the cabi-
net. Open the doors and remove the evaporator
drain pan be removing the screws along the
edges. Remove the evaporator fan grill. The
thermometer sensing element is secured to the
evaporator fan plenum.
Loosen the screw securing the element.
Remove the element and thermometer. Insert
new element and retighten screw. Finish as-
sembly in reverse order. Be sure to run the
sensing element of the new thermometer
through the hole I the cabinet face prior to se-
curing it to the evaporator fan plenum.
ELECTRICAL ENCLOSURE –
The electrical enclosure contains the de-
frost time clock and terminal

Page 6
boards. For servicing convenience, access is
gained by removing the top decorative panel
and electrical box cover. THE CABINET
SUPPLY BREAKERS SHOULD BE DIS-
CONNECTED BEFORE REMOVING THE
ENCLOSURE COVER.
The cabinet electrical supply breakers
should be disconnected before removing the
enclosure cover, and before service work ore
maintenance of any kind is performed.
DEFROST TIME CLOCK –
The timer is factory pre-set for one de-
frost cycle per day at 12:00 a.m., with a 40
minute failsafe. The timer must be adjusted
to the proper time of day when the cabinet is
started. The timer is adjusted by turning the
knurled adjustment knob in the center of the
dial face counter-clockwise until the time indi-
cator corresponds with the correct time of
day.
The defrost pins should be checked for
tightness. The timer will require re-adjusting
after a power failure of the cabinet supply or
if it is turned off for extended periods of time.
If an additional defrost is required due to am-
bient or cabinet usage conditions, do not put a
defrost during the middle of the day.
Put any additional defrost during the
night or at a time when the cabinet has the
lowest usage.
Defrost is time initiated and tempera-
ture terminated. If the thermostat should fail,
the timer is equipped with a failsafe set at 40
minutes that will allow defrost to terminate on
time.
DEFROST HEATER THERMOSTAT –
The defrost heater thermostat is
clamped to the evaporator outlet tube. It
is a bi-metal thermostat that is tied in se-
ries with the evaporator fans for a delay
and with defrost time clock solenoid to
end defrost when the temperature has
been satisfied. The evaporator fans will
not come on until the thermostat senses
32ºF and defrost will terminate when the
stat senses 58ºF.
DEFROST HEATER REPLACEMENT
–
The defrost heaters are firmly em-
bedded in the evaporator and held in
place with spring clips. To remove the
heater, first remove all the spring clips
and pull the defective heater out of the
slots in the evaporator, starting at the
wire supply lead.
The replacement heater should be
firmly seated in the slots by using a small
block of wood and a mallet. After the
new heater is in place, replace all of the
spring retaining clips to assure heater re-
tention. One lead of the defective heater
may be used to pull the new leads
through the cabinet to the respective ter-
minals as marked on each lead.
NOTE: Care must be taken to
make sure the drain stub is
correctly inserted in the cabinet
drain tube for proper drainage.

Page 7
LIGHTING –
Interior lighting is provided by incan-
descent lamps. The lamps have protective
shields which can be removed for bulb re-
placement. The lights are equipped with
switches mounted in the upper left hand cor-
ner of the door opening, that allow the lights
to come on when the door is opened. The
switches are connected in series.
FRAME HEATERS –
The cabinet is equipped with frame
heaters around each door. These are ther-
mostatically controlled and will not come on
until the cabinet is at operating temperature.
FRAME HEATER REPLACEMENT –
To replace the cabinet frame heater
wires, first remove the vinyl breaker strips
by pulling the outer edge away from the cabi-
net. Replace wires exactly as removed, pull-
ing the leads through the plastic conduit. Af-
ter connections have been made, check the
heaters for operation. Replace the plastic
breakers by reversing the removal proce-
dure.
EXPANSION VALVE ADJUSTMENT –
Expansion valve must be adjusted to
fully feed the evaporator. Before attempting
to adjust the valve make sure the evaporator
is either clean or only lightly covered with
frost, and that the cabinet is within 10º of its
expected operation temperature. Adjust the
expansion valve as follows:
1. Attach two sensing probes to the evapora-
tor, one under the clamp holding the ex-
pansion valve sensing bulb and the other
securely taped to one of the return bends
two thirds of the way through the evapo-
rator circuit. Some “hunting” of the ex-
pansion valve is normal
2. The valve should be adjusted so that dur-
ing the hunting the greatest difference
between the two probes is 3º to 5º F.
3. Remove valve stem cover and turn valve
stem counter-clockwise to decrease tem-
perature difference between the probes.
4. To increase temperature difference of
probes, turn the valve stem clockwise.
With this adjustment, during a portion of
the hunting the temperature differences
between the two probes may be less than
3º F, or at times as low as 0º F.
5. Make adjustments of no more than one
half turn of the valve stem at a time and
wait for at least fifteen minutes before
rechecking probe temperature and mak-
ing further adjustments. Replace and
tighten cover of the valve stem.
REFRIGERATION –
As stated previously, this case is a self-
contained system featuring semi-hermetic
compressor and thermostatic expansion
valve. The condenser is of a bare tube con-
struction and SHOULD BE PERIODI-
CALLY CLEANED TO MAINTAIN EFFI-
CIENT OPERATION
If it should become necessary to leak
test the system, please adhere to the following
notice:

Page 8
Because of the CFC atmospheric considerations
being taken today, we ask that leak testing be
done with refrigerant 22 mixed with nitrogen. If
the condensing unit nameplate designates a re-
frigerant other than R-22, remove all R-22 from
the immediate area to avoid confusion after leak
testing and evacuating the unit. Recharge the
unit with proper refrigerant.
LEAK TESTING –
The test gas cylinder must be equipped
with a pressure gauge and regulator so that sys-
tem test pressures do not exceed maximum allow-
able limits. Do not ever use anything other than a
R-22/Nitrogen mixture for leak testing.
Attach a refrigerant test gas cylinder to
your service manifold and connect the manifold
to the charging port on the liquid line valve.
Charge an R-22/Nitrogen mixture into the sys-
tem, raising the pressure to the unit’s nameplate
for the low side and high side pressures. Using an
electronic detector, carefully check the entire sys-
tem for leaks. Take special care to inspect all
brazed and flare connections.
EVACUATION –
After the system is proven leak tight, thor-
oughly evacuated the system according to the fol-
lowing procedure:
1. Discharge the refrigerant-nitrogen mixture,
allowing it to blow from the system as rapidly
as possible, into an empty cylinder. Be sure
that all service valves and solenoid valves are
open to allow all of the mixture to be dis-
charged.
2. Connect a deep-drain vacuum pump to
both the high and low side of the sys-
tem. Pull a vacuum on the system to at
least 1500 microns.
3. Break the vacuum by adding refriger-
ant into the system until the pressure is
above 0 PSIG. Always charge the re-
frigerant line into the system through a
new drier in the charging manifold line.
A 16 cubic inch drier is sufficient for
this purpose.
4. Repeat steps 2 and 3 two more times,
the third time evacuating the system to
500 microns.
OPERATING DATA –
The following is typical data for
USL models based on lab tests, and may
vary under field operating conditions.
Ambient Temperature 75ºF
Head Pressure 225 psi
Suction Pressure 3-5 psi
Discharge Air -25ºF
Return Air -10ºF
COMPRESSOR –
The compressor is mounted on
springs and banded for shipping purposes
and this band needs to be cut upon installa-
tion. DO NOT LOOSEN THE COM-
PRESSOR MOUNTING BOLTS AS
THESE ARE FACTORY PRE-SET FOR
PROPER RIDING ON THE SPRINGS.
RECEIVER –
The receiver should not be confused
for a filter-drier or muffler. The receiver is

Page 9
in the liquid line after the condenser and just
ahead of the filter-drier. It has sweat connec-
tions, and is in a horizontal position. The
manufacturer may label the receiver as a muf-
fler or a drier but it is, in fact, an empty shell.
CRANKCASE PRESSURE REGULATOR -
The USL-2 with R404a refrigerant em-
ploys a crankcase pressure regulator in the
suction line. The CPR is set for 12 psi. The
purpose of the valve is to maintain a low suc-
tion pressure on start-up so that the compres-
sor will start properly. On start-up, the valve
will hold the suction pressure at the desired
setting until the suction pressure has dropped
below the setting, then the valve will open.
If it becomes necessary to check or reset
the setting, the case must be warm such as af-
ter a defrost cycle or from an initial warm
case condition. Put a suction compound gauge
on the compressor suction valve, start the com-
pressor. If the pressure needs to be reduced
turn the adjustment screw clockwise or, coun-
terclockwise to raise the pressure. DO NOT
SET THE VALVE BASED ON THE NAME-
PLATE AMPERAGE RATING AS THE
PRESSURE SETTING WILL BE TOO HIGH
AND THE COMPRESSOR WILL NOT
START PROPERLY.