236400 Packged Chiller.pdf

03-01-20

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SECTION 23 64 00

PACKAGED WATER CHILLERS

PART 1 - GENERAL

1.1 DESCRIPTION

A. Hermetic Direct-Drive Scroll Compressors air-cooled chillers complete with accessories.

1.2 RELATED WORK

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

B. Section 01 35 26, Safety Requirements

C. Section 23 05 93, TESTING, ADJUSTING, AND BALANCING FOR HVAC

D. Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS.

E. 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.

D. FTT-10: Echelon Transmitter-Free Topology Transceiver.

1.4 QUALITY ASSURANCE

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

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

Standard

F. Refer to ASHRAE Standard 15, Safety Standard for Refrigeration System, for refrigerant vapor detectors and monitor.

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):

370-2015................Sound Rating of Large Outdoor Refrigerating and

Air-Conditioning Equipment

495-2005(R2009).........Refrigerant Liquid Receivers

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550/590-2018............Standard for Water Chilling Packages Using the

Vapor Compression Cycle

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

Engineers (ASHRAE):

15-2019.................Safety Standard for Mechanical Refrigeration

Systems

D. American Society of Testing Materials (ASTM):

C 534/C534M-2017........Preformed, Flexible Elastomeric Cellular

Thermal Insulation in Sheet and Tubular Form

C 612-2014..............Mineral-fiber Block and Board Thermal

Insulation

E. National Electrical Manufacturing Association (NEMA):

250-2014................Enclosures for Electrical Equipment (1000 Volts

Maximum)

F. National Fire Protection Association (NFPA):

70-2017.................National Electrical Code

G. Underwriters Laboratories, Inc. (UL):

1995-2015............... 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. Hermetic direct drive scroll compressors air cool water chillers, including motor starters, control panels, and vibration isolators.

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 PACKAGED WATER CHILLERS

A. General: Units are constructed of galvanized steel frame with galvanized steel panels and access doors. Component surfaces are finished with a powder-coated paint. Each unit ships with full operating charges of refrigerant and oil.

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B. HERMETIC DIRECT DRIVE SCROLL COMPRESSOR AIR-COOLED WATER CHILLERS:

Factory-assembled and-tested hermetic direct drive scroll compressor air cool water chillers, complete with evaporator, compressors, motor, starters, integral or remote 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: Packaged water chillers shall be rated within the scope of the AHRI Certification Program and display the AHRI Certified mark as a visual confirmation of conformance to the certification section of

AHRI Standard 550/590 (I-P) and ANSI/AHRI Standard 551/591 (SI).

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. If chillers are required to operate at less than 25 percent of full unit rated capacity, specify provision for hot gas by-pass, to operate the unit stable at any stage of capacity reduction.

C. Capacity of a single air-cooled chiller shall not exceed 250 Tons

(Standard AHRI Conditions).

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

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

E. Compressor (Hermetic 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, centrifugal oil pump, and oil charging valve. Capacity control shall be by on-off compressor cycling of single and multiple compressors and hot gas bypass. Overload protection shall be included with compressor.

H. Refrigerants Circuit: The package water chiller 40-130 ton shall have dual refrigerant circuits. Each refrigerant circuit has hermetic scroll compressors piped in parallel with a passive oil management system to maintains proper oil levels. Each refrigerant circuit shall

23 64 00 - 4 include filter drier, electronic expansion valve, and liquid line and discharge service valves.

I. 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.

J. Condenser:

1. Air-cooled microchannel (MCHE) condenser coils are all aluminum brazed fin construction. Each slab is split horizontally into separate condensing and subcooling coil are connected by either copper tube or receiver tank. The maximum allowable working pressure of the condenser is 650 psig (44.8 bar). (MCHE) Condensers are factory proof tested to 650 psig (44.8 bar) and leak tested at

585 psig (40.3 bar). Coils can be cleaned with high pressure water.

Optional round tube and plate fin (RTPF) air-cooled condenser coils have aluminum fins mechanically bonded to internally-finned copper tubing. The condenser coil has an integral subcooling circuit. The maximum allowable working pressure of the condenser is 650 psig

(44.8 bar). Condensers are factory proof tested at 650 psig (44.8 bar) and leak tested at 585 psig (40.3 bar). Direct-drive vertical discharge condenser fans are balanced. Three-phase condenser fan motors with permanently lubricated ball bearings and external thermal overload protection are provided. Units start and operate from 0°F to 125°F (-18°C to 52°C) for wide ambient. Wide ambient allows operation down to 0°F which is accomplished by a variable speed fan on each circuit that modulates to maintain system differential pressure. 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.

K. Evaporator: Braze plate heat exchanger is made of stainless steel with copper as the braze material. It is designed to withstand a refrigerant side working pressure of 430 psig (29.6 bar) and a waterside working pressure of 150 psig (10.5 bar). Evaporator is tested at 1.1 times

23 64 00 - 5 maximum allowable refrigerant side working pressure and 1.5 times maximum allowable water side working pressure. It has one water pass.

Immersion heaters protect the evaporator to an ambient of -20°F (-

29°C). The evaporator is covered with factory-installed 0.75 inch

(19.05 mm) Armaflex II or equal (k=0.28) insulation. Foam insulation is used on the suction line. Water pipe extensions with insulation go from the evaporator to the edge of the unit.

L. 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.

M. Refrigerant Receiver: Provide a liquid receiver for chiller units when system refrigerant charge exceeds 80 percent of condenser refrigerant volume. Liquid receivers shall be horizontal-type, designed, fitted, and rated in conformance with AHRI 495. Receiver shall be constructed and tested in conformance with Section VIII D1 of the ASME Boiler and

Pressure Vessel Code. Each receiver shall have a storage capacity not less than 20 percent in excess of that required for fully charged system. Each receiver shall be equipped with inlet, outlet drop pipes, drain plug, purging valve, and relief devices as required by ASHRAE

Standard 15.

N. High Ambient: The unit shall start and operate from 32˚F to 125˚F (0˚C to 52˚C).

O. Low-Temperature Processing: Temperature sensor at compressor discharge, enables leaving evaporator fluid temperature between 10˚F (-

12.2˚C) and 40˚F (4.4˚C). Leaving evaporator fluid temperatures below

10˚F (-12.2˚C) are also possible for specific applications.

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

Q. Chiller control panel shall either reside on the "LonTalk FTT-10a network", and provide data using LonMark standard network variable types and configuration properties, or BACnet interworking using ARCNET or MS/TP physical data link layer protocol for communication with building automation control system.

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

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T. Motor Starter: Unit-Mounted Starter control panel shall be per UL 1995.

The starter is an across-the-line configuration, factory mounted and fully pre-wired to the compressor motor and control panel. A factory-installed, factory -wired 820 VA control power transformer provides all unit control power (120 Vac secondary).

U. Dual High Head Pump Package: Dual Pump shall be integrated in package water chiller.

1. Dual Pump Package shall include two high head pumps, VFD, expansion vessels, drainage valves, shut-off valves at entering and leaving connections.

2. The pump package shall have single point power integrated into the chiller unit power with separate factory wired control panel. The control of the pump shall be integrated into the chiller controller.

The CH530 displays evaporator pump starts and run-times. Freeze protection down to an ambient of -20˚F (-29˚C) shall be included as standard. The cold part of the pumps package shall be insulated.

3. The chiller control both pumps through a lead/lag and failure/recovery functionality.

4. A variable speed drive shall be installed in an additional panel to control the pump. The inverter is adjusted upon start up to balance the system flow and head requirements.

5. Buffer Tank: The water buffer tank shall be factory-installed. The tank shall be engineered for continuous flow and shall be fully insulated as standard for freeze protection.

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. Concrete base is specified in Section 03 30 00, CAST-IN-PLACE

CONCRETE

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2. Vibration isolator types and installation requirements are specified in Section 23 05 41, NOISE and VIBRATION CONTROL FOR HVAC PIPING and

EQUIPMENT

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 refrigerant piping as specified in Section 23 23 00, REFRIGERANT PIPING and ASHRAE Standard 15.

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

E. 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. Extend vent piping from the relief valve and purge system to the outside.

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 COR 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.

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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.

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 COR.

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.

E. The Commissioning Agent will observe startup and contractor testing of selected equipment. Coordinate the startup and contractor testing schedules with the COR and Commissioning Agent. Provide a minimum of 7 days prior notice.

F. Provide services of manufacturer’s technical representative for four hours to instruct VA personnel in operation and maintenance of computer room air conditioning equipment.

3.4 COMMISSIONING

A. Provide commissioning documentation in accordance with the requirements of Section 01 91 00 GENERAL COMMISSIONING REQUIREMENTS and Section 23

08 00 – COMMISSIONING OF HVAC SYSTEMS for all inspection, start up, and contractor testing required above and required by the System Readiness

Checklist provided by the Commissioning Agent.

B. Components provided under this section of the specification will be tested as part of a larger system. Refer to Section 23 08 00 –

COMMISSIONING OF HVAC SYSTEMS and related sections for contractor responsibilities for system commissioning.

3.5 DEMONSTRATION AND TRAINING

A. Provide services of manufacturer’s technical representative for four hours to instruct VA personnel in operation and maintenance of units.

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Coordinate this training with that of the cooling tower, if furnished together.

B. Submit training plans and instructor qualifications in accordance with the requirements of Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS.

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