Hussmann USL-2, Installation And Service Instructions Manual

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