236400 Packaged Water Chillers.pdf

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SECTION 23 64 00

PACKAGED WATER CHILLERS

PART 1 - GENERAL

1.1 DESCRIPTION

A. Scroll air-cooled chillers complete with accessories.

1.2 RELATED WORK

A. Section 00 72 00, GENERAL CONDITIONS.

B. Section 01 00 00, GENERAL REQUIREMENTS.

C. Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

D. Section 23 21 13, HYDRONIC PIPING.

1.3 DEFINITION

A. Engineering Control Center (ECC): The centralized control point for the intelligent control network. The ECC comprises of personal computer and connected devices to form a single workstation.

B. BACNET: Building Automation Control Network Protocol, ASHRAE Standard

135.

C. Ethernet: A trademark for a system for exchanging messages between computers on a local area network using coaxial, fiber optic, or twisted-pair cables.

1.4 QUALITY ASSURANCE

A. Refer to Paragraph, QUALITY ASSURANCE, in Section 23 05 11, COMMON WORK

RESULTS FOR HVAC and STEAM GENERATION, and comply with the following.

B. Refer to PART 3 herein after and Section 01 00 00, GENERAL REQUIREMENTS for test performance.

C. Comply with AHRI requirements for testing and certification of the chillers.

D. Refer to paragraph, WARRANTY, GENERAL CONDITIONS, except as noted below:

1. Provide a 5-year motor, and compressor warranty to include materials, parts and labor.

E. Refer to OSHA 29 CFR 1910.95(a) and (b) for Occupational Noise Exposure

Standard

1.5 APPLICABLE PUBLICATIONS

A. The publications listed below form a part of this specification to the extent referenced. The publications are referenced in the text by the basic designation only.

B. Air Conditioning, Heating and Refrigeration Institute (AHRI):

370-01..................Sound Rating of Large Outdoor Refrigerating and

Air-Conditioning Equipment

495-1999 (R2002)........Refrigerant Liquid Receivers

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550/590-03..............Standard for Water Chilling Packages Using the

Vapor Compression Cycle

560-00..................Absorption Water Chilling and Water Heating

Packages

575-94..................Methods for Measuring Machinery Sound within

Equipment Space

C. American Society of Heating, Refrigerating, and Air-Conditioning

Engineers (ASHRAE):

ANSI/ASHRASE-15-2007....Safety Standard for Mechanical Refrigeration

Systems

GDL 3-1996..............Guidelines for Reducing Emission of Halogenated

Refrigerants in Refrigeration and Air-

Conditioning Equipment and Systems

D. American Society of Mechanical Engineers (ASME):

2007 ...................ASME Boiler and Pressure Vessel Code, Section

VIII, "Pressure Vessels - Division 1"

E. American Society of Testing Materials (ASTM):

C 534/ C 534M-2008......Preformed, Flexible Elastomeric Cellular

Thermal Insulation in Sheet and Tubular Form

C 612-04................Mineral-fiber Block and Board Thermal

Insulation

F. National Electrical Manufacturing Association (NEMA):

250-2008................Enclosures for Electrical Equipment (1000 Volts

Maximum)

G. National Fire Protection Association (NFPA):

70-2008.................National Electrical Code

H. Underwriters Laboratories, Inc. (UL):

1995-2005............... Heating and Cooling Equipment

1.6 SUBMITTALS

A. Submit in accordance with Specification Section 01 33 23, SHOP

DRAWINGS, PRODUCT DATA, and SAMPLES.

B. Manufacturer's Literature and Data.

1. Scroll water chillers, including motor starters, control panels, and vibration isolators, and remote condenser data shall include the following:

a. Rated capacity.

b. Pressure drop.

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c. Efficiency at full load and part load WITHOUT applying any tolerance indicated in the AHRI 550/590/Standard.

d. Refrigerant

e. Fan performance (Air-Cooled Chillers only.)

f. Accessories.

g. Installation instructions.

h. Startup procedures.

i. Wiring diagrams, including factory-installed and field-installed wiring.

j. Sound/Noise data report. Manufacturer shall provide sound ratings. Noise warning labels shall be posted on equipment.

C. Maintenance and operating manuals for each piece of equipment in accordance with Section 01 00 00, GENERAL REQUIREMENTS.

D. Run test report for all chillers.

E. Product Certificate: Signed by chiller manufacturer certifying that chillers furnished comply with AHRI requirements. The test report shall include calibrated curves, calibration records, and data sheets for the instrumentation used in factory tests.

PART 2 - PRODUCTS

2.1 ROTARY-SCREW AND SCROLL AIR-COOLED WATER CHILLERS

A. General: Factory-assembled and-tested rotary-screw or scroll water chillers, complete with evaporator, compressors, motor, starters, integral condenser, and controls mounted on a welded steel base. The chiller unit shall consist of two compressors minimum, but not more than eight, mounted on a single welded steel base. Where compressors are paralleled, not more than two shall be so connected and not less than two independent refrigerant circuits shall be provided. Chiller shall be capable of operating one of the following refrigerants: HCFC-

134a or HCFC-410a.

B. Performance: Provide the capacity as shown on the drawings. Part load and full load efficiency ratings of the chiller shall not exceed those shown on the drawings. Provide hot gas by-pass, to operate the unit stable at any stage of capacity reduction.

C. Applicable Standard: Chillers shall be rated and certified according to

AHRI 550/590, and shall be stamped in compliance with AHRI certification.

D. Acoustics: Sound pressure levels shall not exceed the following specified levels. The manufacturer shall provide sound treatment if

23 64 00 - 4 required to comply with the specified maximum levels. Testing shall be in accordance with AHRI requirements.

OCTAVE BAND Overall

63 125 250 500 1000 2000 4000 8000 dB(A)

E. Compressor (Scroll Type): Three dimensional, positive-displacement, hermetically sealed design, with suction and discharge valves, crankcase oil heater and suction strainer. Compressor shall be mounted on vibration isolators. Rotating parts shall be factory balanced.

Lubrication system shall consist of reversible, positive displacement pump, strainer, oil level sight glass, and oil charging valve. Capacity control shall be by on-off compressor cycling of single and multiple compressors and hot gas bypass.

F. Refrigerants Circuit: Each circuit shall contain include an expansion valve, refrigerant charging connections, hot-gas muffler, compressor suction and discharge shutoff valves, replaceable-core filter drier, sight glass with moisture indicator, liquid-line solenoid valve and insulated suction line.

G. Refrigerant and Oil: Sufficient volume of dehydrated refrigerant and lubricating oil shall be provided to permit maximum unit capacity operation before and during tests. Replace refrigerant charge lost during the warranty period, due to equipment failure, without cost to the Government.

H. Condenser:

1. Air-cooled integral condenser as shown on the drawings and specified hereinafter.

2. Integral Condenser: Condenser coils shall be extended surface fin and tube type, seamless copper tubes with aluminum fins. For corrosion protection, see Paragraph 2.7 below. Condenser coils shall be factory air tested at 3105 kPa (450 psig). Condenser fans shall be propeller type, directly connected to motor shaft. Fans shall be statically and dynamically balanced, with wire safety guards. Condenser fan motors with permanently lubricated ball bearings and three-phase thermal overload protection. Unit shall start -18°C (0°F) with external damper assemblies. Units shall have grilles factory mounted to prevent damage to coil surfaces.

I. Evaporator: Shell and tube design with seamless copper tubes roller expanded into tube sheets. Designed, tested, and stamped in accordance

23 64 00 - 5 with applicable portions of ASME Boiler and Pressure Vessel Code, Section VIII, for working pressure produced by the water system, but not less than 1035 kPa (15 psig). Refrigerant side working pressure shall comply with ASHRAE Standard 15. Shell shall be constructed of carbon steel. For the waterside of liquid cooler the performance shall be based on a water velocity not less than 1 m/s (3 fps) with a maximum water velocity of 3 m/s (10 fps) and a fouling factor 0.0000176 m2 degrees C (0.0001 hr. sq. ft.) degrees F/Btu. Evaporator for packaged air-cooled chiller units designed for outdoor installation shall be protected against freeze-up in ambient temperature down to -30 degrees C

(-20 degrees F) by a resistance heater cable under insulation with thermostat set to operate below 3 degrees C (37 degrees F) ambient.

J. Insulation: Evaporator, suction piping, compressor, and all other parts subject to condensation shall be insulated with 20 mm (0.75 inch) minimum thickness of flexible-elastomeric thermal insulation, complying with ASTM C534.

K. Controls: Chiller shall be furnished with unit mounted, stand-alone, microprocessor-based controls in NEMA 3R enclosure, hinged and lockable, factory wired with a single point power connection and separate control circuit. The control panel provide chiller operation, including monitoring of sensors and actuators, and shall be furnished with light emitting diodes or liquid-crystal display keypad.

1. Following shall display as a minimum on the panel:

a. Date and time.

b. Outdoor air temperature.

c. Operating and alarm status.

d. Entering and leaving water temperature-chilled.

e. Operating set points-temperature and pressure.

f. Refrigerant temperature and pressure.

g. Operating hours.

h. Number of starts.

i. Current limit set point.

j. Maximum motor amperage (percent).

2. Control Functions:

a. Manual or automatic startup and shutdown time schedule.

b. Condenser water temperature.

c. Entering and leaving chilled water temperature and control set points.

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d. Automatic lead-lag switch.

3. Safety Functions: Following conditions shall shut down the chiller and require manual reset to start:

a. Loss of chilled water flow.

b. Loss of condenser water flow (for water-cooled chillers only).

c. Low chilled water temperature.

d. Compressor motor current-overload protection.

e. Freeze protection (for air-cooled chillers).

f. Starter fault.

g. High or low oil pressure.

h. Recycling pumpdown.

L. The chiller control panel shall provide leaving chilled water temperature reset based on 4-20 ma or 0-10 VDC signal from Energy

Control Center (ECC).

M. Provide contacts for remote start/stop, alarm for abnormal operation or shutdown, and for Engineering Control Center (ECC).

N. Chiller control panel shall reside on the BACnet interworking using

ARCNET or MS/TP physical data link layer protocol for communication with building automation control system.

O. Auxiliary hydronic system and the chiller(s) shall be interlocked to provide time delay and start sequencing as indicated on control drawings.

P. Motor: Compressor motor furnished with the chiller shall be in accordance with the chiller manufacturer and the electrical specification. Starting torque of motors shall be suitable for driven machines.

PART 3 – EXECUTION

3.1 EXAMINATION

A. Examine roughing-in for concrete equipment bases, anchor-bolt sizes and locations, piping and electrical to verify actual locations and sizes before chiller installation and other conditions that might affect chiller performance, maintenance, and operation. Equipment locations shown on drawings are approximate. Determine exact locations before proceeding with installation.

3.2 EQUIPMENT INSTALLATION

A. Install chiller on concrete base with isolation pads or vibration isolators.

1. Existing concrete base to be reused.

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2. Vibration isolator types and installation requirements are as per chiller manufacturer recommendations.

3. Anchor chiller to concrete base according to manufacturer’s written instructions.

4. Charge the chiller with refrigerant, if not factory charged.

5. Install accessories and any other equipment furnished loose by the manufacturer, including remote starter, remote control panel, and remote flow switches, according to the manufacturer written instructions and electrical requirements.

6. Chillers shall be installed in a manner as to provide easy access for tube pull and removal of compressor and motors etc.

B. Install refrigerant monitoring and safety equipment in accordance with

ASHRAE Standard 15.

C. Install thermometers and gages as recommended by the manufacturer and/or as shown on drawings.

D. Piping Connections:

1. Make piping connections to the chiller for chilled water, condenser water, and other connections as necessary for proper operation and maintenance of the equipment.

2. Make equipment connections with flanges and couplings for easy removal and replacement of equipment from the equipment room.

3.3 STARTUP AND TESTING

A. Engage manufacturer's factory-trained representative to perform startup and testing service.

B. Inspect, equipment installation, including field-assembled components, and piping and electrical connections.

C. After complete installation startup checks, according to the manufacturers written instructions, do the following to demonstrate to the VA that the equipment operate and perform as intended.

1. Check refrigerant charge is sufficient and chiller has been tested for refrigerant leak.

2. Check bearing lubrication and oil levels.

3. Verify proper motor rotation.

4. Verify pumps associated with chillers are installed and operational.

5. Verify thermometers and gages are installed.

6. Verify purge system, if installed, is functional and relief piping is routed outdoor.

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7. Operate chiller for run-in-period in accordance with the manufacturer’s instruction and observe its performance.

8. Check and record refrigerant pressure, water flow, water temperature, and power consumption of the chiller.

9. Test and adjust all controls and safeties. Replace or correct all malfunctioning controls, safeties and equipment as soon as possible to avoid any delay in the use of the equipment.

10. Prepare a written report outlining the results of tests and inspections, and submit it to the VA.

D. Engage manufacturer’s certified factory trained representative to provide training for 8 hours for the VA maintenance and operational personnel to adjust, operate and maintain equipment, including self-contained breathing apparatus.

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