INSTALLATION AND MAINTENANCE MANUAL
Ceiling-Temp, Dual-Flo and Height Saver Unit Coolers
Bulletin No. IOM 119.1
January, 2002
Inspection
When the equipment is received, t he number of crates
and cartons should be checked against the bill of lading
for possible shortages. Any damage should be noted
immediately and a report given to the freight carrier and
the factory. It is the customer’s responsibility to file
all freight claims with the carrier.
Installation
Installation and maintenance must be preformed by
qualified personnel who are familiar with the local codes
and regulations and who are experienced with this
type of equipment. Unit name plates should be checked
to make sure voltages are in agreement with the power
available. Caution: Avoid contact with sharp edges and
coil surface as they are potential hazards.
Location
Determine the best location for the unit cooler in the
room to be refrigerated. Placement of the unit should
be centered in the room and away from an open door
to keep warm, outside air from being drawn into the
unit.This dual discharge unit, draws air up through the
fan blades and discharges out the coils length. Proper
clearances should be maintained for proper air flow
and service access to the unit as follows: 18” minimum
between each coil and wall: 12” on each end of the
unit. Before unit is raised into position all packaging
should be removed making sure the unit is not set on
the drain fitting or refrigerant connections. The unit
should be supported on 5/16” minimum rod hangers
at all mounting slots. To meet NSF requirements, the
unit must be positioned flush with the ceiling and all
gaps properly caulked.
Drain Line
The drain line should be pitched at a minimum of 4”
per foot to allow proper drainage and should exit the
room as soon as possible. The drain line should be
insulated and sealed where it passes thru the wall and
trapped outside the refrigerated area and protected from
freezing. In rooms with temperatures below 34° F, the
drain line should be heated and insulated.
Refrigerant Connections
Refrigerant connections should be installed in
accordance with all applicable codes and using good
refrigeration practices. A suction line trap must be
installed prior to any risers in the suction line. Horizontal
suction lines should be sloped to provide proper oil
return to the compressor. Suction lines should be
properly insulated to prevent sweating and higher return
gas temperatures.
Expansion V alve
Expansion valves are to be installed in accordance with
the valve manufacturer’s recommendations. The external
equalizer line must be connected. Proper location of the
sensing bulb is extremely important to the performance of
the coil.Good thermal contact to the suction line is essential. On solder type valves, a wet cloth wrapped around
the valve during installation will help protect it from overheating and damage during the installation process.
Superheat settings should be checked after the system
has balanced out at the desired room temperature. On
systems sized for a 10° to 12° F TD, the valve should be
adjusted to maintain 4° to 6° F superheat. Higher evaporator TD will allow a higher superheat setting. On multiple evaporator systems, the piping should be arranged
such that the flow from any valve cannot affect the bulb of
an other.
Wiring
Wiring should be done in accordance with all national
and local codes. Electric defrost units are supplied with
a temperature sensing defrost termination switch which
will terminate the defrost at a preset temperature. A fan
delay switch is also provided to allow the coil to cool
down prior to the fans restarting after the defrost cycle.
The time clock should be adjusted to have a maximum
30 minute override to prevent overheating and steaming
of the coils. Typically one to two defrosts per day are
recommended however, the number of defrosts are ultimately dictated by the usage of the box and the actual
amount of frost buildup on the coils.
Evacuation
Proper evacuation is essential prior to charging of the
system. This avoids many problems that may arise due
to lack of detail in this step. After charging, the system
should be checked through all cycles to ensure proper
operation.
General Maintenance
General maintenance involves an occasional cleaning of
dirt accumulation on the fans, fan guards and coils. The
motors are life lubricated and do not require any regular
maintenance.