10 • Installation & Operation
INSTALLATION & OpERATION
Service
UNDER CASE ACCESS
The bumper and kickplate must be removed to gain access to the drain clean out and electrical connections. Disassemble the bumper and
kickplate by removing the 2 or 3 metal screws located in the kick rail. The bumper assembly can be lifted up and removed from the case. The
kickplate can be removed, exposing the drain and electric enclosure cover. An optional top electrical box is available for easier installation and
accessibility.
EVAPORATOR
The evaporator coil, located at the rear bottom of the case, is factory-assembled with distributor, expansion valve, and other refrigeration
components. To inspect the coil, remove the center or left of center coil cover. A small inspection window is located at the rear of the case. To
inspect the entire coil, remove the remaining coil covers and raise the metal evaporator cover.
EXPANSION VALVE
Unless otherwise specified, a superheat, externally-adjustable, equalized thermostatic expansion valve with pressure limiting charge (low temp
only) is mounted to the evaporator coil. The valve is not preset. Adjust the superheat setting for maximum coil effectiveness. Typical superheat
settings are between 6°F and 10°F. Close coupled systems should use the higher superheat setting to minimize the chance of liquid flood back.
To adjust the expansion valve, remove the right end coil cover. Remove the cap from the bottom of the valve. When looking at the valve stem
end, turn the valve stem counterclockwise to decrease superheat. Turn the valve stem clockwise to increase superheat. Measure the suction
line temperature at the expansion valve sensing bulb and compare it to the suction temperature corresponding to the saturated pressure. Make
sure that line pressure drop is taken into account.
Turn the valve stem only 1/4 turn at a time and allow sufficient time (20 to 30 minutes) for the valve to settle before making any further
adjustments. Replace the valve stem cap after the valve superheat has been adjusted. BE CERTAIN THE VALVE STEM CAP IS WIPED DRY
FIRST.
!
CAUTION!
DISCONNECT POWER TO THE CASE BEFORE SERVICING ELECTRICAL COMPONENTS TO AVOID PERSONAL
INJURY AND DAMAGE TO THE UNIT.
EVAPORATOR FANS
Air is circulated throughout the case with 115 volt low temperature fan motors. These motors must be operating at all times, except during
defrost in low temp cases. Fan motors should be replaced with motors having the same characteristics including type, physical size, lubricant
temperature range, wattage, and RPM. Fan blades should be replaced with factory original equipment part.
CONDENSATE EVAPORATION SYSTEM
Zero Zone remote cases can be equipped with an automatic condensate evaporation system. The system uses a pump and drain pan located
behind the kickplate and a condensate evaporator pan mounted on the top of the case.
Condensate water and any liquid spilled in the case drains out into the drain pan. The pump is equipped with a float that turns the pump on
when there is a sufficient liquid level. Liquid is pumped through a plastic hose through a check valve and into the condensate evaporation
pan. The evaporation pan is equipped with a heater and a float switch to turn on when the heater is submerged in liquid. When the heater is
energized, the pan will be extremely hot and should not be touched. The pump and condensate pan should be cleaned regularly. Any spilled
product should be cleaned to prevent odors.
