shall be mounted on vibration isolators. Rotating parts shall be factory
balanced. Main bearings shall be rolling-element type. Lubrication
systems shall be centrifugal pump type including oil level sight glass and
oil charging valve.
2.1.3.4
Condensers
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NOTE: The selection of the double-tube bundle is a
design function where a steady demand exists for low
grade rejected heat. Where this demand does not
exist or where the heat recovery cannot be
justified, the single-tube bundle should be used.
**************************************************************************
Water-cooled condensers shall have shell-and-tube construction, permitting
tubes to be cleaned from each end by removing water box cover plates or
head and a minimum amount of water piping. Refrigerant side design
pressure shall comply with ASHRAE 15. Water side design pressure shall not
be less than 1034 kPa (gage) 150 psig. Tubes shall be fabricated of
seamless copper tubing, plan or with integral fins, and shall be
individually replaceable and rolled or brazed into copper or steel tube
sheets. Base performance on a water velocity not less than 0.91 m/s 3 fps
nor more than 3.66 m/s 12 fps and a fouling factor of 0.00075. Condenser
shall be [single] [double]-tube bundle type.
2.1.3.5
Liquid Coolers (Evaporators)
Tubes shall be seamless copper. On direct-expansion-type units, each
refrigerant circuit shall be complete with liquid solenoid valve and
expansion device capable of modulating to minimum capacity. For the water
side of liquid cooler, performance shall be based on a water velocity not
less than 0.91 m/s 3 fps nor more than 3.66 m/s 12 fpsand a fouling factor
of 0.00025.
2.1.3.6
Controls, Control Panels, and Gages
**************************************************************************
NOTE: Specify required time delay for type and size
of unit after consulting current literature.
**************************************************************************
**************************************************************************
NOTE: Specify lowest percent of full capacity
required. Check for availability before inserting
number in blank.
**************************************************************************
Provide a control panel fitted with a discharge pressure gage, suction
pressure gage, separate high pressure cutout with manual reset, separate
low pressure cutout, low water temperature cutout with manual reset,
compressor operating control, and manual off-auto switch. Provide oil
pressure gage and low-oil-pressure cutout switch with manual reset for
chillers with positive displacement type oil pumps. Provide signal lights
or other visual "failed" indications for high pressure, low pressure, and
oil pressure protection devices. Multicompressor units shall be provided
with a lead/lag selector switch. Provide a timer to prevent compressors
from short cycling whenever stopped by safety controls. Time delay shall
be not less than [_____] minutes. A pumpdown cycle of the nonrecycling
SECTION 15601N
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