2758 to 34,470 kPa (gage)400 to 5000 psig system, multi-cylinder,
multi-stage, [air] [water] cooled, reciprocating, [belt][direct]-driven,
base-mounted type, rated for continuous duty at [20,682] [_____] kPa (gage)
[3,000] [_____] psig and capacity indicated. Mount compressor, motor,
controls, and instruments on a welded steel base plate. [Provide means to
adjust V-belt tension.] Provide splash lubricated compressor not to exceed
105 rad/sec 1000 rpm, or pressure lubricated compressor not to exceed 188
rad/sec 1800 rpm. Provide three phase squirrel cage induction motor not
exceeding 188 rad/sec 1800 rpm, with voltage characteristics as indicated,
and open drip-proof enclosure. Crankshaft and connecting rods shall be
steel. Frame (crankcase), cylinders, and cylinder heads shall be close
grain cast iron. Fully enclose frame. Provide automatic unloaders to
permit the compressor to start unloaded. Provide [air] [water] cooled
coolers after every stage of compression to cool discharge air to within
[4] [-7] [_____] degrees C [40] [20] [_____] degrees F of ambient air
temperature. Provide automatic condensate drains to drain condensate
during operation and when the compressor stops. Conform to NEMA MG 1for
motor and NEMA ICS 2 and NEMA ICS 6 for controls.
2.1.1
Controls
**************************************************************************
NOTE: Select the first paragraph for only
start-stop control or the second paragraph and
subparagraphs for dual control.
**************************************************************************
[Start-stop control compressors by means of pressure switches [and arrange
for a lead compressor and a lag compressor]. [Lead] compressor shall start
when the pressure falls to [17,235] [_____] kPa (gage) [2,500] [_____] psig
and stop when the pressure reaches [20,682] [_____] kPa (gage) [3,000]
[_____] psig. [Lag compressor shall start when the pressure falls to
[13,788] [_____] kPa (gage) [2,000] [_____] psig and stop when the pressure
reaches [20,682] [_____] kPa (gage) [3,000] [_____] psig.] When both
compressors stop at cutout pressure, the lead and lag positions of
compressors shall be interchanged automatically by means of an electric
[Regulate compressor by dual control. Dual system shall consist of a
combination of constant speed control and an automatic start-and-stop
control by automatic or manual selector switch.]
**************************************************************************
NOTE: Include "Start-and-Stop Control" and
"Constant Speed Control" below only for "Dual
Control" option.
**************************************************************************
2.1.1.1
Start-and-Stop Control
When set for start-and-stop control, motor shall stop automatically when
discharge pressure reaches maximum pressure setting and start automatically
when discharge pressure falls to minimum setting. Cylinders shall unload
during periods of motor shutdown.
2.1.1.2
Constant Speed Control
Compressor shall operate continuously at constant speed.
Provide means to
SECTION 15212N
Page 17
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