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1945 Theatre Catalog, 4th Edition, Page 405 (381)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 405
Page 405

1945 Theatre Catalog, 4th Edition, Page 405

Water-Cooled CoilFWhen water is used for cooling a refrigerant, coils are not visible, but are contained in a shell, which has the appearance of a long, cylindrical tank, mounted horizontally. If the refrigerant or liquid is not being cooled sufiiciently, it may be due to the formation of scale inside the water coils. 1f inadequate cooling is indicated, call your maintenance man.

Defrosting CoilseA coating of ice or frost on a cooling unit acts as insulation and must be removed. Defrosting is usually accomplished by turning the power switch to the tiofi'" position until the ice is completely melted. Never use an ice pick or any other sharp instrument to hasten defrosting. A stream of cold water will loosen it quickly. Never use hot water for defrosting commercial units. Check drains before defrosting. Be sure pans and baffles are supported properly and have sufiicient slant to drain well. Do not place anything on drip pans or baffles, as circulation will be restricted and ice formation may result.


The compressor is the heart of the plant, pumping the refrigerant through the system. The compressor should be kept in first-class condition, so that it will do its job of cooling without working overtime.

Belt-Driven Type-4f the compressor deVelops a knocking noise, shut the unit down immediately before any damage can occur, and call the maintenance man at once. If water-cooled compressors are exposed to freezing temperatures, have your serviceman take the necessary precautions to prevent damage to the machine. Draining of a water-cooled compressor must be handled by an experienced man, to insure that all water is removed from the condenser. The suggestion to give your compressor room to breathe applies to both air- and watercooled compressors. Piling boxes around the compressor causes overheating, and loss of efficiency results and the operating costs go up.

Sealed lypHDue to their design, sealed-type units require a minimum of attention. However, the following points will help to improve refrigeration, reduce operating costs, and prolong the life of the equipment. A thick coating of dust and dirt will hold extra heat in the compressor and reduce its over-all operating efficiency. Such coatings often cause metal surfaces to rust. Do not allow dust and dirt to collect on the condenser, Clean periodically with a brush or vacuum-cleaner? attachment. Always disconnect the extension cord, or turn the supply switch to the iiofim position before cleaning the condenser. Do not pile boxes or other materials around your compressor. Blocked circulation will reduce efficiency, increase operating costs, and cause needless wear on equipment. If the compressor is installed in the machine compartment of a fixture, do not block the grille openings or allow them to be clogged with dirt. Some air-cooled units have a separate fan motor, Your instruction book, dealer, or serviceman will tell you


where and how often to oil it and the type and grade of oil to be used.


In one stage of the refrigeration cycle, the refrigerant gas must be changed into a liquid. In order to do this, heat must be removed from the gas. Air may be used for removing the heat. In such cases, the condenser consists of a coil, through which the refrigerant flows, a fan to blow the air over the coil, and a motor to drive the fan. Condensers cooled by water consist of a coil enclosed in a shell similar to the one described under Water-Cooled Coils. Coils cooled by the evaporation of water consist of the coil, a means of wetting the coil surfaces with a water spray, fan to circulate the air, and a motor to drive the fan. Detailed description of this type of coil may be found under Air- and Water-Cooled Coils.

Air-Cooled CondenserseDo not allow dust and dirt to clog up the air passages of an air-cooled condenser. Before cleaning any part of the compressor, be sure to turn the power-supply switch to the ttoff" position. The condenser should be cleaned frequently with a brush, bicycle pump, or vacuum-cleaner attachment.

Keep coils in good condition by following instructions given under Air-Cooled Coils.

Keep fans in good condition by following instructions given under Motors.

Water-Cooled CondenserseKeep coil in good condition by following the instructions given under Water-Cooled Coils.

Evaporative CondensersaEvaporative condensers are a valuable part of a refrigerating system. It is important to keep them functioning properly in order to effect savings. Evaporative condensers and water towers exposed to freezing temperatures must be properly

drained to prevent damage from freezing. The cooling equipment will probably not be operating when freezing weather occurs, and exposure of watercooIed equipment to temperatures even a little below freezing may cause serious damage. Keep condenser in condition by following the instructions given under Air- and Water-Cooled Coils, Fans, Motors, and Spray Nozzles.


The controls are the brains of the refrigeration system. Without these efficient devices, automatic operation of the equipment would not be possible. If the controls do not operate properly, they should be adjusted by an experienced serviceman, who knows how your particular system was designed to operate.

Refrigerant Controlsalncluded in refrigerant controls are the various types which regulate the fiow of the refrigerant through the system. These consist of automatic and thermostatic expansiOn valves, temperature regulating valves, and others. The correct setting of these valves should be handled only by an experienced serviceman.

Electrical Controls-The group of electrical controls includes devices such as your thermostats, circuit breakers, many of which are used to make-and-break the electric current to start and stop the motor. Since dust and insects may cause the current to are and, thereby, burn contact points, the covers of these controls should be kept tightly in place as a protection against dust and unauthorized tampering. Switches for starting and stopping the equipment and electric devices which control air-conditioning and refrigeration machinery have contact points which may deteriorate. When electric circuits are broken, a spark occurs, and this may cause pitting of

THE COMPRESSORS shown here are two 50-horsepower, 5l/4-by-4l/4-inch condensing units, installed for theatre use. The compressor is the heart of the plant, pumping the refrigerant through the system. The compressor should be kept in first-class condition, so that it will do its iob of cooling without working overtime. Beside the pictured belt-drive type, there is a sealed-type of compressor. Always follow the makers suggestions in maintenance.

1945 Theatre Catalog, 4th Edition, Page 405