EXHIBIT I - SPECIFICATIONS.pdf

EXHIBIT I

Department of Agriculture and Consumer Services

Central Energy Plant Air-Cooled Chiller Replacement

Air Cooled, Rotary-Screw Water Chillers 236426 - 1

Air-Cooled, Rotary-Screw Water Chiller

PART 1 - GENERAL

1.01 SUMMARY

A. This exhibit includes design, performance criteria, refrigerants, controls, and installation requirements for air-cooled rotary screw packaged chillers.

(INSTALLATION IS NOT PART OF THIS BID)

1.02 REFERENCES

A. AHRI 550/590 - Standard for Water Chilling Packages using the Vapor Compression

Cycle

B. AHRI 370 - Sound Rating of Large Outdoor Refrigerating and Air-Conditioning

Equipment

C. ASHRAE 15 - Safety Code for Mechanical Refrigeration

D. ASHRAE 90.1 - Energy Efficient Design of New Buildings

E. ASME - Boiler and Pressure Vessel Code SEC VIII, Division 1

1.03 SUBMITTALS

A. Submit dimensional plan and elevation view drawings, weights and loadings, required clearances, location and size of all field connections, electrical requirements and wiring diagrams.

B. Submit product data indicating rated capacities, accessories and any special data.

C. Submit manufacturer's installation instructions.

1.04 REGULATORY REQUIREMENTS

A. Comply with codes and standards specified.

B. Chiller must be built in an ISO 9001 classified facility.

1.05 VERIFICATION OF CAPACITY AND EFFICIENCY

A. All proposals for chiller performance must include an AHRI approved selection method.

1.06 DELIVERY, HANDLING AND STORAGE

A. Comply with manufacturer's installation instructions for rigging, unloading, and transporting chillers.

B. Chiller shall be capable of withstanding 0⁰F to 110⁰F storage temperatures for an indefinite period of time.

1.07 WARRANTY

A. Provide a complete manufacturer 10-year parts, labor, and refrigerant warranty.

PART 2 - PRODUCTS

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2.01 ACCEPTABLE MANUFACTURERS

A. Trane, Daikin, Carrier, York

2.02 CHILLER DESCRIPTION

A. The vendor shall furnish and deliver the air-cooled water chiller with screw compressors as shown in this bid specification.

2.03 CHILLER OPERATION

A. Low ambient operation; Chiller shall be able to start and operate in ambient conditions down to 0⁰F and up to 105⁰F. Low ambient operation is accomplished with factory installed and tested protection.

B. Chiller shall be capable of operating with a leaving solution temperature range 40⁰F to

68⁰F (4.4 to 20⁰C) without glycol.

C. Chiller shall be capable of starting up with 95⁰F (35⁰C) entering fluid temperature to the evaporator. Maximum water temperature that can be circulated with the Chiller not operating is 108⁰F (52⁰C)

D. Chiller shall provide evaporator freeze protection and low limit control to avoid low evaporator refrigerant temperature trip-outs during critical periods of chiller operation.

Whenever this control is in effect, the controller shall indicate that the chiller is in adaptive mode. If the condition exists for more than 30 seconds, a limit warning alarm relay shall energize.

2.04 COMPRESSORS

A. Construct chiller using semi-hermetic, variable speed drive, helical rotary screw compressor per circuit.

B. Provide compressor motor that is suction gas cooled with robust construction and system design protection.

C. Provide oil lubrication system with oil charging valve and oil filter to ensure adequate lubrication during starting, stopping, and normal operation.

D. Provide compressor heater to evaporate refrigerant returning to compressor during shut down. Energize heater when compressor is not operating.

E. Provide compressor with automatic capacity reduction equipment consisting of capacity control via variable speed drive and/or slide valve. Compressor must start unloaded for soft start on motors.

Air Cooled, Rotary-Screw Water Chillers 236426 - 3

F. Chiller shall be capable of operation down to 25% load without hot gas bypass.

2.05 EVAPORATOR

A. The evaporator shall be designed, tested, and stamped in accordance with ASME code for a refrigerant side working pressure of 200 psig. Waterside working pressure shall be

150 psig.

B. Insulate the evaporator with a minimum of 1.25 inch (K=0.28) UV rated insulation.

C. Evaporator heaters shall be factory installed and shall protect chiller down to -20⁰F (-

29⁰C). Contractor shall wire separate power to energize heat tape and protect evaporator while chiller is disconnected from the main power.

D. Provide shell and tube type evaporator, seamless or welded steel construction with cast iron or fabricated steel heads, seamless internally and externally finned copper tubes, roller expanded into tube sheets.

E. Provide ability to remove evaporator tubes from the heat exchanger.

F. Evaporator shall have cleanable tubes

G. Provide water drain connection, vent and fittings. Factory installed leaving water temperature control and low temperature cutout sensors.

H. Water connections shall be grooved pipe.

I. Proof of flow shall be provided by the equipment manufacturer, mechanically installed and electrically wired, at the factory of origin.

2.06 FANS

A. Low sound fans shall be balanced and direct driven.

B. All condenser fan TEAO motors have permanently lubricated ball bearings and external overload protection.

C. Each condenser fan shall have an integrated drive to provide variable speed for optimized efficiency and lower part load sound.

2.07 CONDENSER

A. Construct condenser coils of aluminum fins mechanically bonded to internally finned copper tube. The condenser coils shall have an integral subcooling circuit and shall be designed for 350 psig or higher working pressure. Leak tested at 1.1 times working pressure.

B. Condenser coils shall be transverse design. If coils are not transverse design, provide coil protection for shipping.

Air Cooled, Rotary-Screw Water Chillers 236426 - 4

2.08 ENCLOSURES/CHILLER CONSTRUCTION

A. Unit panels, structural elements and control boxes are constructed of galvanized steel and mounted on a bolted galvanized steel base. Unit panels, control boxes and the structural base are finished with a baked on powder paint.

B. Control panel doors shall have door stays.

C. Mount starters and Terminal Blocks in a UL 1995 rated weatherproof panel provided with full opening access doors. The circuit shall be a lockable, through-the-door type with an operating handle and clearly visible from outside of chiller indicating if power is on or off.

D. The coating or paint system shall withstand 500 hours in a salt-spray fog test in accordance with ASTM B117.

2.09 CHILLER MOUNTED ADAPTIVE FREQUENCEY DRIVE (AFD)

A. The water chiller shall be furnished with a fluid cooled Adaptive Frequency Drive (AFD) as shown on the drawings.

B. The AFD efficiency shall be 97% or better at full speed and full load. Fundamental displacement power factor shall be a minimum of 0.96 at all loads for AFD. All other starters shall have a minimum displacement power factor of 0.85.

C. Power semi-conductor and capacitor cooling shall be from a liquid or air cooled heatsink.

D. Unit shall have a single point power connection.

E. A molded case standard interrupting capacity circuit breaker shall be factory pre-wired with terminal block power connections and equipped with a lockable external operator handle, making it available to disconnect the chiller from main power.

F. A control power transformer shall be factory-installed and factory-wired to provide unit control power.

G. Unit wiring shall run in liquid-tight conduit.

H. High short circuit current rating (SCCR) of 65A.

2.10 REFRIGERANT CIRCUIT

A. All chillers shall have 2 refrigeration circuits, with 1 or 2 compressor on each circuit.

B. Provide for refrigerant circuit:

1. Liquid line shutoff valve

2. Suction service valve

3. Discharge service valve

4. Filter (replaceable core type)

Air Cooled, Rotary-Screw Water Chillers 236426 - 5

5. Liquid line sight glass.

6. Electronic expansion valve sized for maximum operating pressure

7. Charging valve

8. Discharge and oil line check valves

9. High side pressure relief valve

10. Integrated oil loss sensor

C. Full operating charge of R134a and oil.

2.11 CONTROLS

A. A color, touch sensitive liquid crystal display (LCD) shall be unit mounted and a minimum of 7" diagonal. Graphical Icons provide links to sub menus on the subsystems operations.

B. Display shall consist of a menu driven interface with easy touch screen navigation to organized sub-system reports for compressor, evaporator, and motor information as well as associated diagnostics.

C. The chiller control panel shall provide password protection of all setpoints

D. The controller shall have the ability to display all primary sub-system operational parameters on dedicated trending graphs.

E. Chilled water temperature control shall be microprocessor-based, proportional and integral controller to show water and refrigerant temperature, refrigerant pressure, and diagnostics.

F. The front of the chiller control panel shall display the following in clear language, without the use of codes, look-up tables, or gauges:

1. Run time.

2. Number of starts.

3. Current chiller operating mode.

4. Chilled water set point and set point source.

5. Electrical current limit set point and set point source.

6. Entering and leaving evaporator water temperatures.

7. Saturated evaporator and condenser refrigerant temperatures.

8. Evaporator and condenser refrigerant pressure.

9. Oil tank pressure.

10. Intermediate oil pressure in the compressor.

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11. Compressor motor current per phase.

12. Compressor motor percent RLA.

13. Compressor motor voltage per phase.

14. Phase reversal/unbalance/single phasing and over/under voltage protection.

15. Low chilled water temperature protection.

16. High and low refrigerant pressure protection.

17. Load limit functions (both current based or pulldown rate based) to limit compressor loading on high return water temperature.

18. Condenser fan sequencing to automatically cycle fans in response to load, expansion valve pressure, condenser pressure, and differential pressure to optimize chiller efficiency.

19. Display diagnostics.

20. Oil pressure control based off of maintaining system differential pressure.

21. Compressors: Status (on/off), %RLA, anti-short cycle timer, and automatic compressor lead-lag.

22. Oil loss indication.

G. Weatherproof control panel shall be mounted on chiller, containing starters, power and control wiring, factory wired with terminal block power connection. Provide primary and secondary fused control power transformer.

H. The chiller controller will automatically take action to prevent chiller shutdown due to abnormal operating conditions associated with: evaporator refrigerant temperature, high condensing pressure and motor current overload.

I. Provide the following safety controls with indicating lights or diagnostic readouts.

1. Low chilled water temperature protection.

2. High refrigerant pressure.

3. Low oil flow protection.

4. Loss of Oil diagnostic

5. Loss of chilled water flow.

6. Contact for remote emergency shutdown.

7. Motor current overload.

8. Phase reversal/unbalance/single phasing.

9. Over/under voltage.

Air Cooled, Rotary-Screw Water Chillers 236426 - 7

10. Failure of water temperature sensor used by controller.

11. Compressor status (on or off).

J. Provide the following operating controls:

1. A variable method to control capacity in order to maintain leaving chilled water temperature based on PI algorithms. Five minute solid state anti-recycle timer to prevent compressor from short cycling. Compressor minimum stop-to-start time limit shall be 2 minutes.

2. Load limit functions to limit compressor loading on high return water temperature to prevent nuisance trip outs.

3. High condenser pressure limit controls that unloads compressors to keep head pressure under control and help prevent high pressure nuisance trip outs on days when outside ambient is above design.

4. Compressor current limit controls that unloads compressors to help prevent current overload nuisance trip outs.

5. Low ambient lockout control with user adjustable setpoint.

6. Condenser fan sequencing which adjusts the speed of all fans automatically in response to ambient, condensing pressure and expansion valve pressure differential thereby optimizing chiller efficiency.

K. Provide user interface on the front of the panel. If display is on the inside of the panel, then a control display access door shall be provided to allow access to the display without removal of panels. Provide user interface with a minimum of the following features:

1. Leaving chilled water setpoint adjustment from touch panel input

2. Entering and leaving chilled water temperature output

3. Percent RLA output for each compressor

4. Pressure output of condenser

5. Pressure output of evaporator

6. Ambient temperature output

7. Voltage output

8. Current limit setpoint adjustment from LCD input.

L. The chiller control panel shall provide leaving chilled water temperature reset based upon return water temperature.

Air Cooled, Rotary-Screw Water Chillers 236426 - 8

M. Digital Communications to BAS system shall consist of a BACnet MS/TP interface via a single twisted pair wiring.

2.12 SOUND

A. Acoustics: Manufacturer must provide both sound power and sound pressure data in decibels, per AHRI 370. A-weighted sound pressure at 30 feet should be provided at

100%, 75%, 50% and 25% load points to identify the full operational noise envelope.

B. Chiller shall ship with a muffler on each rotary screw compressor and very low noise condenser fans to meet the scheduled sound levels. If chiller does not meet sound levels, chiller manufacturer shall provide additional attenuation features.

2.13 OPTIONS AND ACCESSORIES

A. Chiller shall have full architectural louvers panels.

B. Chiller shall ship with elastomeric Isolators

END OF SECTION