Williams Ref OT1 Installation Manual

This manual covers the Installation, Operation and Routine Maintenance requirements
for the following Williams Refrigeration products:

Overnight Thaw Cabinets

Provided the instructions in this Operating Manual are read and implemented correctly,
the optimum performance and reliability of your equipment should be maintained.

The Williams Overnight Thaw Cabinet has a temperature parameter set as follows:

+0°C (32°F) / +3°C (37°F)

Declaration of Conformity References:
Low Voltage Directive 2006/95/EC
Machinery Directive 2006/42/EC
Electromagnetic Compatibility Directive 2004/108/EC
Pressure Equipment Directive 97/23/EC
Waste Electrical and Electronic Equipment Directive (WEEE) 2002/96/EC
Restriction on Use of Certain Hazardous Substances Directive (RoHS) 2002/95/EC

CFC Free Refrigerant

Williams Refrigeration declares that all products manufactured by Williams Refrigeration
comply with the above directives as they apply to those products, and those products are
therefore declared to be in conformity with the provisions of the above legislation.

Model No.:

Serial No.:

OPERATING MANUAL for
OVERNIGHT THAW CABINETS

Refrigerant Designation Global Warming Potential

HFC - R134a 1300

HFC - R404a 3260

INSTALLATION

Removal of Redundant Cabinets

Please ensure the old / redundant cabinet and refrigeration equipment are disposed of safely and legally. It is
recommended that doors are removed prior to disposal in order to ensure safety.

Unpacking

Remove all external and interior packing and accessories. Ensure all such material is disposed of safely.

Ventilation

It is essential to ensure that the room in which the unit is to be installed has adequate ventilation. Refrigerators generate
a considerable amount of heat and, if operated in a small unventilated room in warm weather, they will quickly cause the
room temperature to become excessive. This could cause the motor to overheat and possibly damage the windings. At the
very least, such an installation will cause the unit to use an excessive amount of electricity. A single door unit usually
generates 1200W of heat and a two door version - 1800W (these figures are approximate).

In addition to ventilation in a room, please ensure that cabinets with top-mounted systems have 500mm clearance
between the cabinet top and ceiling for engineer access and ventilation, with 50mm clearance provided around the unit
to ensure efficient and effective performance. Do not block vents by stacking boxes on top or in front of the unit as this
could affect performance.

Castors

The cabinet should stand level to ensure correct operation of self-closing doors and proper drainage of condensate
from the evaporator.
Models fitted with castors and non-adjustable, therefore a level platform / floor should be provided where unit is to be
located. Where swivel and brake castors are fitted and when unit has been positioned, please ensure brakes have
been activated by pressing metal bar down. Remember to release brakes before trying to move unit.

Mains Connection

The unit comes fitted with a moulded plug for safety and must be earthed. If plug or cable should fail, please contact
the spares office on [phone] for a replacement.

If the cabinet has been laid on its back or tipped, DO NOT switch on immediately. Leave in an upright position
for at least 1 hour before switching on.

Connection to Main Drains

The Overnight Thaw requires connection to a main drain with a standard 1 1/2” fitting.

Shelf/Slide Fitting

When positioning the slides present the slide to the racking by holding it in the opposite hand to the side of the
cabinet you are installing the slides. Offer the slide at a 45° angle as shown in Figure 1. Once in place let slide drop
into position creating a horizontal ledge on which the shelves will sit.

Shelf Weight Distribution

Before loading, allow cabinet to reach normal operating temperature.

When loading the unit, please ensure that load is equally distributed throughout and ensure air can circulate around
and through stored products. Ensure all items are covered and that raw and cooked foods are stored separately.

Fig. 1

Loading the Cabinet

Food placed inside the unit should be packed in such a way as to encourage thawing. For example, a cardboard box
full of frozen hamburgers could take days to thaw out if out into the unit within the cardboard box. However, if the
hamburgers are unpacked, loaded onto trays and placed inside the unit they will thaw in a matter of hours. For fastest
thawing, food should be uncovered as any type of covering will insulate food.

NB: Since the unit partially untilises the food to lower the temperature, it is recommended that the unit be
operated fully loaded whenever possible for amximum efficiency.

THERMOMETER

The controller is marked in Centigrade or Fahrenheit.
The Thermometer should be checked daily to ensure that correct temperature is being maintained.

CONTROL PANEL

GENERAL OPERATION OF THE OVERNIGHT THAW CABINET

The Overnight Thaw Cabinet is designed to control the thawing of frozen food. The principle of the unit is that it is
loaded with frozen food the afternoon prior to the day the food is required. The unit must be loaded in such a way as
to encourage thawing. Products should be on single trays and removed from their packaging.
The unit has two functions, firstly it is a refrigerator with a temperature range of 0°C to +4°C, secondly it is a heating
unit with a temperature range of -1°C to +2°C.
The refrigeration circuit operates immediately the unit is switched on and the temperature will reduce until it is within
the safe storage range, 0°C to +4°C. When frozen food is placed inside the unit, the unit temperature will drop to below

-1°C which will switch on the heating circuit.
As the temperature reaches +2°C the heating circuit will turn off and the cold food will again reduce the temperature
to -1°C causing the cycle described to be repeated.
The refrigeration / heating cycle is repeated until the temperature of the food is incapable of reducing the unit
temperature to -1°C.
At this stage no further heat is required from the electric heaters and just the heat from the fan(s) will be sufficient to
continue the thawing process. However if at any time the temperature goes up to +4°C, the refrigeration cycle will
come back in place and reduce it to +1°C, thereby avoiding any possibility of the food temperature rising to an unsafe
level.

PLEASE NOTE: Due to the special operation of the equipment the standby button on the controller is disabled.

Adjusting the Operating Temperature

NB: All machines are preset at the factory, however conditions on site will vary compared with test conditions
and it may be necessary to perform the above adjustments several times in order to obtain a perfect
temperature cycle.

To adjust the operating temperature press and hold the

key. Use

and

keys to adjust.