Specifications
Cat 604-5 37
Engineering Guide Specifications
B Equal Products - Equipment manufactured by [ENTER
MANUFACTURER NAME HERE] may be acceptable as
an equal. Naming these products as equal does not imply
that their standard construction or configuration is
acceptable or meets the specifications. Equipment proposed
“as equal”, must meet the specifications including all
architectural, mechanical, electrical, and structural details,
all scheduled performance and the job design, plans and
specifications.
2.2 UNIT DESCRIPTION
A Provide and install as shown on the plans a factory
assembled, charged, and run-tested water-cooled packaged
centrifugal chiller. Chillers shall have no more than two oil-
free, magnetic bearing, semi-hermetic centrifugal
compressors (no exceptions). Each compressor shall have
an integrated variable-frequency drive operating in concert
with inlet guide vanes for optimized full and part load
efficiency. On two-compressor units, the evaporator and
condenser refrigerant sides and the expansion valve shall
be common and the chiller shall be capable of running on
one compressor with the other compressor or any of its
auxiliaries inoperable or removed.
Each chiller shall be factory run-tested on an AHRI
approved test stand with water at job conditions (excluding
glycol applications). Operating controls shall be adjusted
and checked. The refrigerant charge shall be adjusted for
optimum operation and recorded on the unit nameplate.
Units operating with 50-Hz power shall be tested with a 50-
Hz power supply. Any deviation in performance or opera-
tion shall be remedied prior to shipment and the init
retested if necessary to confirm repairs or adjustments.
2.3 DESIGN REQUIREMENTS
A General: Provide a complete water-cooled, semi-hermetic
oil-free centrifugal compressor water chiller as specified
herein. The unit shall be meet standards in Section 1.2. In
general, unit shall consist of one or two magnetic bearing,
completely oil-free centrifugal compressors, refrigerant,
condenser and evaporator, and control systems including
integrated variable frequency drive, operating controls and
equipment protection controls. Chillers shall be charged
with refrigerant HFC-134a. If manufacturer offers a chiller
using any HCFC refrigerant, manufacturer shall provide, in
writing, documentation signed by an officer of the
company assuring refrigerant availability and price
schedule for a 20-year period.
B The entire chiller system, including all pressure vessels,
shall remain above atmospheric pressure during all
operating conditions and during shut down to ensure that
non-condensables and moisture do not contaminate the
refrigerant and chiller system.
If any portion of the chiller system is below atmospheric
pressure during either operation or shut down, the
manufacturer shall include, at no charge:
1 A 20-year purge maintenance agreement that provides
parts, labor, and all preventative maintenance required
by the manufacturer’s operating and maintenance
instructions.
2 A complete purge system capable of removing non-
condensables and moisture during operation and shut-
down.
3 The manufacturer shall also include at no charge for a
period of 20 years an annual oil and refrigerant analysis
report to identify chiller contamination due to vacuum
leaks. If the analysis identifies water, acid, or other
contaminant levels higher than specified by the
manufacturer, the oil and/or refrigerant must be replaced
or returned to the manufacturer’s original specification at
no cost to the owner.
4 The manufacturer shall include a factory-installed and
wired system that will enable service personnel to readily
elevate the vessel pressure during shutdown to facilitate
leak testing.
C Performance: Refer to chiller performance rating.
D Acoustics: Sound pressure for the unit shall not exceed the
following specified levels. Provide the necessary acoustic
treatment to chiller as required. Sound data shall be
measured in dB according to AHRI Standard 575 and shall
include overall dBA. Data shall be the highest levels
recorded at all load points.
2.4 CHILLER COMPONENTS
A Compressors:
1 The unit shall utilize magnetic bearing, oil-free, semi-
hermetic centrifugal compressors. The compressor drive
train shall be capable of coming to a controlled, safe stop
in the event of a power failure.
2 The motor shall be of the semi-hermetic type, of
sufficient size to efficiently fulfill compressor
horsepower requirements. It shall be liquid refrigerant
cooled with internal thermal sensing devices in the stator
windings. The motor shall be compatible with variable
frequency drive operation.
a If the compressor design requires a shaft seal to
contain the refrigerant, the manufacturer shall supply
a 20 year parts and labor warranty on the shaft seal
and a lifetime refrigerant replacement warranty if a
seal failure leads to refrigerant loss, or the chiller
manufacturer shall assume all costs to supply and
install a self contained air conditioning system in the
mechanical space sized to handle the maximum heat
output the open drive motor. The energy required to
operate this air conditioning system shall be added to
the chiller power at all rating points for energy
evaluation purposes.
Octave Band
Overall
dBA
63 125 250 500 1000 2000 4000 8000