SECTION 15684

CENTRIFUGAL WATER CHILLERS

PART 1 GENERAL

SECTION INCLUDES

Chiller package.

Charge of refrigerant and oil.

Controls and control connections.

Chilled water connections.

Condenser water connections.

Auxiliary water connections.

Starters.

Electrical power connections.

RELATED SECTIONS

Section 15170 - Motors.

Section 15252 - Vibration Isolation.

Section 15260 - Piping Insulation

Section 15510 - Hydronic Piping.

Section 15535 - Refrigeration Piping and Specialties.

Section 15540 - HVAC Pumps.

Section 15712 - Induced Draft Cooling Tower.

Section 15714 - Blow Thru Cooling Tower.

Section 15952 - Controls and Instrumentation.

Section 15990 - Testing, Adjusting, and Balancing.

Section 16180 - Equipment Wiring Systems.

REFERENCES

ANSI/ASHRAE 15 - Safety Code for Mechanical Refrigeration.

ANSI/ASHRAE 90A - Energy Conservation in New Building Design.

ANSI/ASME SEC 8 - Boiler and Pressure Vessel Code.

ANSI/UL 465 - Central Cooling Air Conditioners.

ARI 550 - Centrifugal or Rotary Water - Chilling Packages.

SUBMITTALS

Submit shop drawings under provisions of Section [01300.] [01340.]

Submit shop drawings indicating components, assembly, dimensions, weights and loadings, required clearances, and location and size of field connections. Indicate equipment, piping and connections, valves, strainers, and thermostatic valves required for complete system.

Submit product data under provisions of Section [01300.] [01340.]

Submit product data indicating rated capacities, weights, specialties and accessories, electrical requirements and wiring diagrams.

Submit written certification that components of package not furnished by manufacturer have been selected in accordance with manufacturer's requirements.

Submit manufacturer's installation instructions under provisions of Section [01300.] [01340.]

Submit performance data indicating energy input versus cooling load output from 0 to 100 percent of full load[.] [at specified and minimum condenser water temperature.]

OPERATION AND MAINTENANCE DATA

Submit operation data under provisions of Section [01700.] [01730.]

Include start-up instructions, maintenance data, parts lists, controls, and accessories. Include trouble-shooting guide.

Submit maintenance data under provisions of Section [01700.] [01730.]

QUALIFICATIONS

Manufacturer: Company specializing in the manufacture of the products specified in this Section with minimum [three] [_____] years [documented] experience [and minimum [three] [_____] years [documented] experience with the model specified in this Section.]

REGULATORY REQUIREMENTS

Conform to ARI 550 code for testing and rating of centrifugal chillers.

Conform to ANSI/UL 465 code for construction of centrifugal chillers [.] [and provide UL label.]

Conform to ANSI/ASME SEC 8 Boiler and Pressure Vessel Code for construction and testing of centrifugal chillers.

Conform to ANSI/ASHRAE 15 code for construction and operation of centrifugal chillers.

Provide certification of inspection for conforming [authority having jurisdiction] [_______________] approval.

DELIVERY, STORAGE, AND HANDLING

Deliver products to site under provisions of Section [01600.] [01610.]

Store and protect products under provisions of Section [01600.] [01620.]

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

Protect units from physical damage. Leave factory shipping covers in place until installation.

WARRANTY

Provide [two] [five] [_____] year warranty under provisions of Section [01700.] [01740.]

Warranty: Include coverage for [compressor] [compressor motor] [evaporator] [condenser] [complete chiller package as manufactured and delivered to site] including [materials] [and] [labor.] [only.]

MAINTENANCE SERVICE

Furnish service and maintenance of chillers for period of [one] [two] [five] [_____] years from Date of Substantial Completion.

PART 2 PRODUCTS

MANUFACTURERS

[__________________________________] Product [__________.]

[__________________________________] Product [__________.]

[__________________________________] Product [__________.]

Substitutions: Under provisions of Section [01600.]

[01630.]

MANUFACTURED UNITS

Provide factory assembled and tested, packaged, water cooled, liquid chillers consisting of centrifugal compressors, compressor motor, condenser[s], evaporator, refrigeration accessories, instrument and control panel including gages and indicating lights, auxiliary components and accessories, and motor starters. Construction and ratings shall be in accordance with ARI 550.

Units shall have Energy Efficiency Rating (EER) not less than prescribed by ANSI/ASHRAE 90A.

Provide [_____] centrifugal water chillers, [each] having minimum capacity of [___] tons ([___] W) of refrigeration when delivering [_____] gpm ([_____] L/sec) of chilled water at [_____] degrees F ([_____] degrees C). No less than 0.0005 fouling factor when supplied with [_____] gpm ([_____] L/sec) of condenser water at [_____] degrees F ([_____] degrees C) with condenser fouling factor of not less than [0.0005] [0.001], with [R-11] [R-12] [R-22] refrigerant, and maximum power input of [_____] kW. Water head loss thru evaporator [_____] feet ([_____] Pa) maximum and thru condenser [_____] feet ([_____] Pa) maximum.

COMPRESSORS

Compressor Casing: Cast iron, horizontally or vertically split with machined passages, leak tested with refrigerant trace gas to 45 psig (310 kPa). Provide sight glass for monitoring compressor rotation.

Impellers: Single or multi-stage, in-line design, fully shrouded, statically and dynamically balanced, overspeed tested to 20 percent over operating speed, mounted on heat treated forged or rolled steel shaft, nonferrous, labyrinth seals between stages.

Guide Vanes: Modulating radial blade dampers, on each stage, with externally mounted electric operator, suitable for capacity reduction to 10 percent of specified load without hot gas bypass when supplied with design entering water quantity and [55 degree F (13 degree C)] [75 degree F [24 degree C)] [design temperature] entering condenser water.

Bearings: Babbitt lined sleeve bearings, self aligning, pressure lubricated.

Gear Box: Double helical design, symmetrical and center supported by spherically seated, self aligning bearing, arranged for inspection without disassembly.

Motor: Hermetically sealed, singled speed, low slip

induction type. Refer to Section 15170.

Lubrication: Direct drive, positive displacement oil pump, with oil cooler, pressure regulator, oil filters, thermostatically controlled oil heater, and motor controls 1/4 hp (187 W) motor. Interlock to start before chiller motor and run after motor is shut down. Provide sight glass for monitoring oil level.

Refrigerant: [Pre-charge unit with [R-12] [R-500].] [Site-charge unit with [R-11] [R-114].]

EVAPORATOR

Provide evaporator of shell and tube type, seamless or welded steel construction with cast iron or fabricated steel heads, seamless copper tubes or red brass tubes with integral fins, rolled or silver brazed into tube sheets. Space tube support sheets approximately 2.5 ft (750 mm).

Design, test, and stamp refrigerant side for [45 psig (310 kPa)] [[_____] psig ([_____] kPa)] working pressure and water side for [150 psig (1034 kPa)] [300 psig (2070 kPa)] working pressure, in accordance with ANSI/ASME SEC. 8.

Provide marine type water boxes, machine welded to heat exchanger with tapped drain and vent connections, and flanged or mechanical joint connections arranged to permit inspection of tubes from either end without disturbing refrigerant and removable without disturbing water piping.

Insulate evaporator and cold surfaces with [0.75 inch (20 mm)] [_____] minimum thick flexible [expanded polyvinyl chloride] insulation with maximum K value of [0.28.] [0.26.]

Provide thermometer wells for temperature controller and low temperature cutout.

Provide refrigerant chambers with baffles to distribute entering liquid and separate liquid from leaving gas.

Provide carbon rupture disc on shell in accordance with ANSI/ASHRAE 15.

Construction and materials shall conform to ANSI B9.1 and ANSI/ASME SEC. 8.

CONDENSERS

Provide condensers of shell and tube type, seamless or welded steel construction with cast iron or fabricated steel heads, seamless copper tubes or red brass tubes with integral fins, rolled or silver brazed into tube sheets. Space tube support sheets approximately 2.5 ft (750 mm). [Provide additional condensers on heat recovery units.]

Design and stamp refrigerant side for [450 psig (3100 kPa)] working pressure, test refrigerant side at [45 psig (310 kPa)] [[_____] psig ([_____] kPa)]; design, test and stamp water side for [150 psig (1034 kPa)] [300 psig (2070 kPa)] working pressure; in accordance with ANSI/ASME SEC. 8.

Provide marine type water boxes, machine welded to heat exchanger with tapped drain and vent connections, and flanged or mechanical joint connections arranged to permit inspection of tubes from either end without disturbing refrigerant and removable without disturbing water piping.

Provide carbon rupture disc on shell in accordance with ANSI/ASHRAE 15.

Provide baffles to ensure even distribution of incoming gas and to concentrate non-condensible gases.

Construction and materials shall conform to ANSI/ASME SEC 8.

PURGE SYSTEM

Provide purge system consisting of motor driven compressor, electrically heated oil separator, and baffled drum, to automatically remove non-condensibles and water vapor.

System shall automatically discharge non-condensibles. Provide for manual blow-off of water vapor. Provide sight glass for monitoring purge condenser drum.

CONTROLS

On or near chiller, mount steel control panel containing solid state, fully automatic operating and safety controls.

Provide the following safety controls arranged so that operating any one will shut down machine and require manual reset:

High refrigerant (condenser) pressure.

Low refrigerant (evaporator) temperature.

Low refrigerant (evaporator) pressure.

High bearing temperature.

Motor winding temperature.

Motor overload.

Provide the following safety controls arranged so that operating any one will shut down machine and automatically reset:

Low chilled water temperature.

Low oil pressure (differential pressure switch).

Chilled water flow switch.

Condenser water flow switch.

Provide the following devices on control panel face:

Machine off-auto switch.

Machine selector switch to allow load, unload, hold or automatic operation.

Sequential start pilot light.

Operating pilot light.

Condenser pressure gage.

Evaporator pressure gage.

Oil pressure gage.

Oil pump pilot light.

Oil pump switch (manual or automatic).

Purge drum pressure gage.

Purge pump pilot light.

Purge pump switch (manual-off-auto).

Purge oil separator heater pilot light.

Purge oil separator heater switch.

Evaporator low temperature cutout pilot light.

Evaporator low pressure cutout pilot light.

Condenser high pressure cutout pilot light.

Demand limit switch.

Motor driven elapsed run time meter.

Provide the following operating controls:

Solid state, chilled water temperature controller which controls electronic guide vane operator [and hot gas bypass] within throttling range setting of 0.8 degrees F (2.5 degrees C) and features adjustable load rate. Locate temperature sensor in [entering] [leaving] chilled water.

Adjustable thirty minute off timer prevents compressor from short cycling.

Demand limit device to manually set maximum current infinitely between 40 percent and 100 percent of full load amperes.

Solenoid valve between heat recovery condenser and receiver to limit refrigerant level in condenser.

STARTER

On or near chiller, mount steel NEMA 1 type enclosure, containing Star Delta closed transition starter, manufactured in accordance with chiller manufacturer's specifications and factory tested.

Enclosure shall be designed for top or bottom cable entry with front access. Door, interlocked with circuit breaker, shall accommodate padlock.

Mount the following devices within enclosure:

Disconnect switch on line side with fuses.

[Standard] [High] interrupting capacity circuit breaker[.] [with ground fault protection.]

Pilot relays to start and stop compressor on signal from chiller control panel.

Electronic overload provides overload protection, protects compressor motor from distribution system irregularities, and provides motor current signal to

chiller capacity control module.

Control power transformer.

Fused control circuits for control circuit, oil pump motor, oil heater, and purge control unit.

Contactor interlocks for communication between starter and control panel.

Capacitors, one per phase, to correct power factor to minimum 95 percent.

Fused disconnect and starter for oil pump.

Relay for remote mounted emergency shut-down switch.

Provide the following devices on starter door:

Starter fault trip indicator and reset.

Overload trip indicator and reset.

Distribution fault trip indicator and reset.

Ground fault trip indicator and reset.

Ammeters, one per phase.

Voltmeters, one per phase.

PART 3 EXECUTION

INSTALLATION

Install in accordance with manufacturer's instructions.

Provide for connection to electrical service. Refer to Section 15952.

Provide for connection to electrical service. Refer to Section 16180. Include for connection of oil pump to [emergency power.] [separately fused circuit.]

Provide for connection of electrical wiring between starter and chiller control panel, oil pump, and purge unit. Refer to Section [16180.] [15952.]

Align chiller on concrete foundations, sole plates, and sub-bases. Level, grout, and bolt in place.

Install units in vibration isolation. Refer to Section 15252.

Provide evaporator connections to chilled water piping. Refer to Section 15510. On inlet, provide [thermometer well for temperature controller,] [thermometer well and thermometer,] [strainer,] [nipple and flow switch,] [flexible pipe connecter,] [pressure gage,] and shut-off valve. On outlet, provide [thermometer well and thermometer,] [flexible pipe connecter,] [pressure gage,] and [shut-off] [balancing] valve.

Furnish and install necessary auxiliary water piping for oil cooling units and purge condensers.

Insulate evaporator and cold surfaces. Refer to Section 15260.

Provide condenser connection to condenser water piping. Refer to Section 15510. On inlet, provide [thermometer well for temperature limit controller,] [thermometer well and thermometer,] [strainer,] [nipple and flow switch,] [flexible pipe connecter,] [pressure gage,] and shut-off valve. On outlet, provide [thermometer well and thermometer,] [flexible pipe connecter,] [pressure gage,] and [shut-off] [balancing] valve.

Arrange piping for easy dismantling to permit tube cleaning.

Provide piping from chiller rupture disc to outdoors.

Size as recommended by manufacturer.

MANUFACTURER'S FIELD SERVICES

Prepare and start systems under provisions of Section [01600.] [01650.]

Provide services of factory trained representative for minimum [one] [_____] days to leak test, refrigerant pressure test, evacuate, dehydrate, charge, start-up, calibrate controls, and instruct Owner on operation and maintenance.

Supply initial charge of refrigerant and oil.

DEMONSTRATION

Provide systems demonstration under provisions of Section [01670.] [_____.]

Demonstrate system operation and verify specified performance. Refer to Section 15990.

SCHEDULES

Drawing_Code CCH-1 CCH-2 CCH-3 Location

Manufacturer

Model Number

Cooling Capacity

Refrigerant

Unit EER

Evaporator

Water Flow

Entering Water Temperature

Leaving Water Temperature

Pressure Drop

Fouling Factor

Condenser

Water Flow

Entering Water Temperature

Leaving Water Temperature

Pressure Drop

Fouling Factor

Heat Recovery Condenser

Water Flow

Entering Water Temperature

Leaving Water Temperature

Pressure Drop

Fouling Factor

Compressor

Maximum Power Input

Starter Type

END OF SECTION