Russell ITA24-126 Installation Manual

INTER-TEMP
INSTALLATION
MAINTENANCE MANUAL

IOM 102.1
NOVEMBER, 2003

MODELS: ITA, ITE, ITG, ITH

AIR, ELECTRIC AND HOT GAS DEFROST

Inspection

When the equipment is received, check the quantity of cartons and crates against the bill of lading.
Inspect all containers for visible damage. Report any damage or shor tages to the freight company
immediately. It is the customers responsibility to file all freight claims to the carrier.

Installation

Installation and maintenance are to be performed by qualified personnel who are familiar with local
codes and regulations. Installers should have previous experience with this type of equipment.
CAUTION: Avoid contact with sharp edges and coil surface.They are potential hazards.

Determine the best location for the unit in the walk-in cooler or freezer. (See system IOM 550)
Place the unit as far as possible from any door openings.This will help to prevent warm, moist air
from being drawn into the unit, reducing the potential for icing problems. Inter-Temp units are draw­through types, which discharge air directly from the fan into the room.Adequate clearance should
be maintained to allow for proper air flow through the unit and to allow for regular maintenance and
service. Allow a minimum of 24” of clearance on all sides of the unit.

Remove all packing materials before the unit is raised into position. Be certain that the unit is not
sitting on the drain fitting or refrigerant connections.The unit should be supported on 3/8” minimum
thickness stainless steel support rods or fasteners at the hanging slots.The unit must be positioned
flush with the ceiling and all gaps properly caulked.

The drain line should be pitched a minimum of 4” per foot to allow proper drainage and should exit
the room as quickly as possible.Do not locate bends, elbows or drain traps within the refrigerated
space. Do not reduce the drain line size. All drain lines must be trapped outside of the enclosure
where the temperature is never below 35 degrees. Drain lines should run to an open drain and
should never be connected directly to a sewage or waste line.Drain lines may be heated and
insulated to prevent freezing.

Wiring

All wiring must be done in compliance with local and national codes. Use only Copper conductors.
Electric defrost units are supplied with a temperature sensing defrost termination switch which will
end the defrost at a preset coil temperature. A high limit control is provided to prevent overheating if
there is a component failure.A fan delay control is installed to allow the coil temperature to drop
below the freezing point of the water condensate on the fins before star ting the fans.

See the unit rating label for electrical requirements.The wiring diagram is located in the end panel of
the unit cooler. Page 3 shown some examples of typical Inter-Temp wiring diagrams.

Expansion valve

Expansion valves should be selected and installed in accordance with the valve manufacturers
recommendations. Units that require externally equalized expansion valves must have the equalizer
line connected.The expansion valve bulb must be clamped securely at the 4 o’clock or 8 o’clock
position on a horizontal run of the suction line. Proper location and full contact of the bulb is
extremely important to the performance of the system.

New expansion valves usually need to be adjusted. Superheat setting should be checked after the
system has run long enough to reach a balanced state. Low temperature systems will usually
operate more efficiently with a superheat setting ranging from 6 to 8 degrees at design room
temperature, medium temp rooms from 8 to 12 degrees.

To obtain evaporator superheat:

1. Measure the suction line temperature at the expansion valve bulb with an accurate electronic
thermometer.

2. Obtain a suction pressure reading at the schrader fitting at the evaporator suction connection.

3. Convert the pressure reading to temperature by using a temperature/pressure conversion chart.

4. Subtract the converted temperature from the measured temperature.The resulting difference
represents the evaporator superheat.

(For close coupled systems, it may be necessary to increase the evaporator superheat to insure the
minimum acceptable superheat at the compressor.)

The maximum recommended evaporator TD for medium temperature rooms is 15 degrees. 12 - 13
degrees is the maximum recommended TD for low temperature systems.

Evacuation

Proper installation recommended must include a deep evacuation of the system (See system IOM

550). A clean/dry system is essential when charging refrigerant.

General Maintenance

Disconnect all electrical power to the unit before inspecting or cleaning. Unit coolers should be

checked periodically and cleaned of all dirt or grease accumulation. Fan blades and guards may
require more frequent cleaning. Do not use ammonia or other cleaning agents that are corrosive to
Copper or Aluminum.The drain pan should be lowered and thoroughly cleaned to prevent any drain
restriction.The fan motors are life lubricated and do not require periodic oiling.

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