SEC. II · SEC. III
SECTION II - EXPLOSION PROOF COOLERS
Explosion proof water coolers are designed to
containing inflammable or explosive mixtures of vapors,
gases or dust. They meet all requirements as defined in
Laboratories for Class I, Groups C and D; Class II,
Groups F and G. Therefore, it is necessary to remove
the cooler from these conditions to a safe working area
before servicing the
refrigeration system or electrical components.
The electrical wiring is run through conduit and
the combination relay-overload and thermostat are
housed in a sealed junction box. To gain access for
servicing, a threaded dome cover is provided.
The refrigeration system is of the hermetic type.
Service procedures mentioned in previous chapters
apply to this cooler.
SECTION III - BELT DRIVEN OR OPEN TYPE REFRIGERATION SYSTEM
Open or belt driven type refrigeration water coolers are
used in areas of odd voltages, D. C. current or other
special applications. They are designed for field
servicing and all parts of the system are replaceable.
The function of the refrigeration cycle is basically
the same as explained in Chapter I, Section II. A
thermostatic expansion valve, instead of a capillary tube,
is used for metering of the refrigerant to the evaporator.
The major difference between the hermetic and
open type refrigeration system is in the compressor and
motor assembly. The open system is supplied with a
crankshaft-cylinder type compressor, which is driven by
an independent motor and V belt. A fan blade mounted
on the motor pulley provides cooling air for the
Service shut-off valves are provided on the
suction and discharge sides of the compressor and at
the outlet of the receiver. These valves allow the service
man to work on the system without the loss of a large
amount of refrigerant.
Maintenance of the water cooler with an open type
refrigeration system should be performed periodically by
a competent refrigeration service man. It is vitally
important for proper operation and long life of the cooler.
The service man when performing these services
1 - Oil Motor
2 - Clean Condenser and check for proper air
3 - Adjust the V belt tension
4 - Check for refrigerant leaks
5 - Correct refrigerant charge and pressures
6 - Check drinking water temperature and ad-
When thermostat needs replacing,
exact factory replacement should be
used. Others may give faulty service.
IMPORTANT - Never return a cooler with an open type
refrigeration system to the factory for repairs without
specific authorization. The design and assembly of this
type cooler is such that all parts can be quickly changed
in the field and frequently at less cost than packing,
handling and freight in shipment to and from the repair
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