replaceable sleeve insert type, steel-backed, antifriction metal wear
surface bearings, or antifriction bearings or a combination thereof.
Aluminum connecting rod bearings shall be integral or replaceable sleeve
insert type. Provide bulls-eye type oil sight glass at crankcase operating
level. Compressors with a rated input of 2 1/4 kW 3 horsepowerand over
shall have forced-feed lubrication with reversible, self-priming, suction
strainer fitted, direct crankshaft drive, positive-displacement pump.
[Open compressor shaft seals shall be oil lubricated and cooled rotary
mechanical type with externally, individually, replaceable wearing
components.] External drive motor enclosures shall be [open drip-proof.]
[totally enclosed.]
2.2.3
Helical Rotary Compressors
Provide positive displacement, oil-injected type, driven by an electric
motor. Solid steel rotors, Society of Automotive Engineers Grade 1141 or
1144. Shaft main bearings shall be either sleeve-design type with leaded
bronze or steel-backed babbit; or frictionless bearing design, ball or
roller type. Provide housings and covers of high-grade cast-iron pressure
castings. Lubrication systems shall lubricate rotors, bearings, shaft seal
as well as rotor sealing and cooling. Provide an oil safety cutout
interlocked with the compressor starter to allow compressor to operate only
when the oil management system is operational. Provide for lubrication of
bearings and shaft seals on shutdown with or without electric power supply.
2.2.4
Accessories
Unit accessories with 1 1/8 kW 1 1/2 horsepower and larger compressor shall
include suction, discharge and liquid gage ported shutoff valves, suction
and discharge service valves, suction strainers, mufflers, crankcase
heaters, and pressure relief. Provide double seated service valves with
gage ports. Provide lube oil pressure gages and failure switches for
forced-feed lubricated open and accessible hermetic compressors. Unless
heaters shall function only when compressor is stopped. [Provide
condensers with purge valves.] [Where low ambient control incorporates
condenser flooding, receiver shall be sized as required.]
2.2.5
Compressors shall start from rest unloaded. [Provide with start-stop
control.] [Provide with capacity modulation.] [Provide not less than
[_____] capacity control steps.]
2.2.6
Condenser, Integral
Provide with [air-cooled] [water-cooled] condenser. [Open compressor unit
rated through 2 1/4 kW 3 horsepower may utilize integrally cast blades of
compressor flywheel or sheave as the air moving device supplemented by a
propeller fan mounted on extended compressor drive motor shaft.] [Provide
condensers and compressors with manufacturer's standard direct-drive
propeller fans which are elastomer mounted in combined, enclosing, guard or
support.] Construct coils with separate subcooling circuit [and circuiting
as indicated,] of copper tubing with aluminum fins. Test coils in
accordance with ASHRAE 15. Provide coils with sheet steel frame and
venturi fan shroud.
SECTION 15602N
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