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The basic principle of operation is as follows: On the suction stroke of the first-stage piston(s), air at atmospheric pressure enters the cylinders through the inlet filter(s) and then the inlet valves located in the head. On the compression stroke of the first-stage piston(s), the air is compressed to an intermediate pressure and discharged through the discharge valves(s) into common manifold(s). From the manifold(s) the air passes through the intercooler tubes, where the heat of first-stage compression is removed. On the suction stroke of the second-stage piston this cooled air enters the second-stage cylinder through the inlet valve. The compression stroke of the second-stage piston compresses the air to the final discharge pressure and forces it out through the discharge valve into the receiver tank or system. If cooling of the discharge air is required, an air-cooled aftercooler should be installed between the compressor discharge and the receiver tank or system.
For maintaining the receiver tank or system air pressure within predetermined limits, the compressor may be operated with automatic start & stop control or constant speed control regulation. The type of regulation used depends upon the application.
ADDITIONAL REFERENCES ___________________________
Unless otherwise stated, dimensions, weights and measurements are provided in standard U.S. measure followed in parentheses by the metric conversion. Any torque values given are stated in inch or foot pounds followed by the Newton-meter equivalent in parentheses. Electrical characteristics are given in voltage-phase-hertz.
RECEIPT & INSPECTION
Ensure adequate lifting equipment is available for unloading and moving the unit to the installation site.
NOTE | Lifting equipment must be properly rated for the |
| weight of the unit. |
•CAUTION | Lift the unit by the shipping skid only. Do not use |
| the motor lifting eye to lift the entire unit. The motor |
| lifting eye is for removing the motor from the unit |
| only. |
•CAUTION! Do not work on or walk under the unit while it is suspended.
Before signing the delivery receipt, inspect for damage and missing parts. If damage or missing parts are apparent, make the appropriate notation on the delivery receipt, then sign the receipt. Immediately contact the carrier for an inspection.
All material must be held in the receiving location for the carrier’s inspection.
Delivery receipts that have been signed without a notation of damage or missing parts are considered to be delivered “clear.” Subsequent claims are then considered to be concealed damage claims. Settle damage claims directly with the transportation company.
If you discover damage after receiving the unit (concealed damage), the carrier must be notified within 15 days of receipt and an inspection must be requested by telephone with confirmation in writing. On concealed damage claims, the burden of establishing that the unit was damaged in transit reverts back to the claimant.
Read the unit nameplate to verify it is the model ordered, and read the motor nameplate to verify it is compatible with your electrical conditions. Make sure electrical enclosures and components are appropriate for the installation environment.
INSTALLATION
SELECTING A LOCATION _____________________________
ELECTRIC MOTOR UNITS. For most electric motor units, select a relatively clean and dry well-lighted indoor area with plenty of space for proper ventilation, cooling air flow and accessibility. Provide 1,000 cubic feet of fresh air per 5 horsepower. Locate the unit at least 15 inches (38 cm) from walls, and make sure the main power supply is clearly identified and accessible.
Unless the electrical components of the unit are specially protected for outdoor use, do not install an electric motor unit outdoors or in an area that will expose the electrical components to rain, snow or sources of appreciable moisture.
WARNING FOR UNITS EQUIPPED
WITH ELECTRIC DRAIN VALVE
•WARNING The electric drain valve incorporates arcing or sparking parts, such as snap switches, receptacles and the like that tend to produce arcs or sparks and, therefore, when located in a garage, the compressor should be in a room or enclosure provided for the purpose, or the electric drain valve should be 18 inches (457 mm) or more above the floor.
GASOLINE ENGINE UNITS. For gasoline engine units, keep the engine at least 3 feet (1 m) away from building walls and other equipment. Install the unit in a location with plenty of space for proper ventilation, cooling air flow and accessibility. Do not install or operate a gasoline engine unit in a confined area.
AMBIENT TEMPERATURE CONSIDERATIONS. Ideal operating temperatures are between 32°F and 100°F (0°C and 37.8°C). If temperatures consistently drop below 32°F (0°C), install the compressor in a heated area. If this is not possible, you must protect safety/relief valves and drain valves from freezing. If temperatures are consistently below 40°F (4.4°C), consider installing an external crankcase heater kit, especially if the compressor has difficulty starting.
•CAUTION Never operate the compressor in temperatures below -15°F (-26.1°C) or above 125°F (51.0°C).
HUMID AREAS. In frequently humid areas, moisture may form in the pump and produce sludge in the lubricant, causing running parts to wear out prematurely. Excessive moisture is especially likely to occur if the unit is located in an unheated area that is subject to large temperature changes.
Two signs of excessive humidity are external condensation on the pump when it cools down and a “milky” appearance in petroleum lubricant.
You may be able to prevent moisture from forming in the pump by increasing ventilation, operating for longer intervals or installing an external crankcase heater kit.
NOISE CONSIDERATIONS. Consult local officials for information regarding acceptable noise levels in your area. To reduce excessive noise, use vibration isolator pads or intake silencers, relocate the unit or construct total enclosures or baffle walls.
