H18.REV

PACKAGED AIR-COOLED WATER CHILLERS (Reciprocating or Centrifugal

NOTE: FINAL COPY: JANUARY, 1987.

Part 1 -	GENERAL

1)	WORK INCLUDED

A.	Work in this Section includes the providing of labor, materials, equipment and services necessary for a complete and safe installation in accordance with the contract documents and all applicable codes and authorities having jurisdiction for the following

1.	Water Chiller Package.

2.	Installation of chiller.

3.	Testing and startup.

4.	Operating Instructions

2)	RELATED WORK AND REQUIREMENTS

A.	Requirements of GENERAL CONDITIONS, DIVISION NO. 1 and Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK apply to all work in this Section

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY SECTIONS DIRECTLY AFFECTING WORK OF THIS SECTION

B.	Related work in following Sections:

1.	PIPING.

2.	CHILLED WATER SYSTEM.

3.	INSULATION.

4.	MOTORS.

5.	MOTOR CONTROLLERS.

6.	AUTOMATIC CONTROL SYSTEMS.

7.	VIBRATION ISOLATION.

8.	NOISE CONTROL.

9.	WATER TREATMENT.

10.	THERMOMETERS, GAUGES AND RECORDING INSTRUMENTS.

11.	BALANCING AIR AND WATER SYSTEMS.

12.	-----.

3)	REFERENCE STANDARDS

A.	Published Specifications' standards, tests or recommended methods of trade, industry or governmental organizations apply to work in this Section

B.	Comply with all applicable national, state and local codes and refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK for additional Reference Standards

4)	QUALITY ASSURANCE

A.	Refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK for Guarantee and other Quality Assurance requirements

5)	SUBMITTALS

A.	Submit the following to Architect and/or Engineer.

1.	Shop drawings and product data.

2.	Manufacturer's installation instructions.

3.	Manufacturer's descriptive literature, operating instructions, and maintenance and repair data

4.	Show on shop drawings equipment, piping and connections, valves, strainers, and thermostatic valves required for complete system

5.	Submit certification that related components not furnished by chiller manufacturer have been selected in accordance with his requirements

6.	Submittal shall include:

a.	Compressor motor data.

b.	Oil pump data.

c.	Foundations: detailed and dimensional.

d.	Controls.

e.	Wiring diagrams.

f.	Factory installation recommendations.

Part 2 -	PRODUCTS

NOTE: TRANE IS THE ONLY MANUFACTURER FOR PACKAGED AIR COOLED CENTRIFUGAL CHILLER WITH HEAT RECOVERY

1)	BASE BID MANUFACTURERS

A.	Trane Co., York Division, Borg Warner Corp., Carrier Corp. and McQuay Div. of McQuay-Perfex, Inc

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS. OPTION 1 APPLIES TO RECIPROCATING CHILLERS ONLY, COMPRISING PARAGRAPHS 2.02 THROUGH 2.06 INCLUSIVE. REFER TO OPTION 2 FOR CENTRIFUGAL CHILLERS

2)	CHILLER UNIT

A.	Provide packaged outdoor chiller unit, factory assembled, in accordance with ARI standard 590. Unit shall be complete with compressors, compressor motors, evaporators, air-cooled condensers, air-cooled condenser fans, fan motors, weatherproof equipment and control panel, interconnecting refrigerant piping and fittings, automatic controls, safety cut-outs, electric starters, insulation and factory applied enamel paint of approved color. Unit shall be supported on 14 gauge welded steel framework of unitized construction. The cabinet shall be galvanized steel, phosphatized and finished with chlorinated vinyl lacquer. Unit shall be factory prewired, tested and charged with Refrigerant 22 and oil, similar to Trane Co. Cold Generator, Model No. CGA

NOTE: NORMALLY, REFRIGERANT 22 IS USED. REVISE ABOVE IF OTHER REFRIGERANT IS USED

B.	Provide separate refrigerant circuit for each compressor. Each refrigerant circuit shall be provided with pressure relief devices, liquid line solenoid valves, with manual lift stem, liquid line shut-off valve, 2 replaceable cartridges similar to Sporlan Control Catchall replaceable core type, combination sight glass and moisture indicator similar to Sporlan See-All, refrigerant charge valve connection, purge check and thermostatic expansion valve complete with external equalizer, superheat adjustment, capillary and bulb similar to Sporlan Valve Co. Provide refrigerant piping made-up with silver brazed joints

C.	Packaged chiller unit shall be factory insulated. Evaporator shall be insulated with a minimum 3/4 inch thick rigid foamed plastic insulation. Insulate refrigerant suction piping as specified in Section INSULATION

3)	COMPRESSORS

A.	Provide direct driven, 1750 rpm, serviceable or rebuildable hermetic single or multiple compressors. Each compressors shall be suitable for unloaded start and shall be provided with unloaders for capacity control, suction strainer, crankcase heater, hot gas muffler, replaceable main bearings, reversible rotating oil pump, suction and discharge service valves, and oil level sight glass

4)	EVAPORATORS

A.	Each evaporator shall be direct expansion shell and tube heat exchanger, constructed in accordance with ASME code for Unfired Pressure Vessels and ASME stamped. The design pressure on the water side shall be 150 psig and on the refrigerant side 225 psig. Tubes shall be copper or red brass with intermediate tube supports at three feet maximum spacing. Heads shall be removable and constructed of cast iron or steel. Provide well for freezestat

5)	CONDENSER

A.	Provide air cooled condenser complete with direct driven propellor type fans, fan motor, extended surface coils, separate circuit for each compressor, sub cooling circuit, accumulator, low ambient temperature control, refrigerant piping, pressure relief devices, liquid line shut off valves, refrigerant charging valved connections and purge check. Propellor fan shall be constructed of anodized aluminum with permanently lubricated ball bearings. Motor shall be provided with built-in overload protection. Air cooled condenser coil shall be seamless copper tube with aluminum fins

NOTE: EDIT SEQUENCE OF OPERATION IN SECTION "AUTOMATIC CONTROL SYSTEMS" TO CORRESPOND WITH THE FOLLOWING PARAGRAPH

6)	UNIT CONTROLS

A.	Provide weatherproof control cabinet, factory-mounted and prewired with the following

1.	Refrigerant suction and discharge pressure gauges, refrigerant dual (low and high) pressure cutout switches with manual reset on high pressure cutout, oil pressure cutout switches, compressor indicating lights, start stop switches, time delay relay to prevent short cycling of compressors, a crankcase heater control to energize crankcase heater when compressor is inoperative, transformer for 120 volt, 60 hz control circuit, manual reset freezestat (bulb located in evaporators shell near chilled water outlet) to stop compressor on low water temperature, terminal block and interlock capability to run only part of the fans for low-noise night operation

NOTE: COORDINATE WITH ELECTRICAL DEPARTMENT.

2.	Combination fused disconnect switch and magnetic starter type controller for each motor

EM

3.	Chilled water temperature controller: cycling and/or unloading compressors to maintain adjustable preset return water temperature

NOTE: FOR UNITS REQUIRING CONSTANT CHILLED WATER TEMPERATURE LEAVING UNIT. FOR MULTI COMPRESSOR UNITS INDEPENDENT SHELL AND TUBE EVAPORATOR IS REQUIRED FOR EACH COMPRESSOR. ALSO CHECK PUMPS AND AUTOMATIC CONTROLS FOR MAINTAINING CONSTANT LEAVING WATER TEMPERATURE

4.	Leaving water temperature controlled to plus or minus 1 deg F by sensor in leaving water piping operating external capacity step unloader

EM

B.	Multiple Unit Operation

NOTE: SELECT APPLICABLE OPTION FORM THE FOLLOWING LISTINGS:

ONTROL

1.	Control all units from single control device. Use anti-recycle/ fixed-off timer

2.	Provide manufacturer's sequence panel to control all units. Use anti-recycle/fixed-off timer

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. REVIEW PROJECT WITH CHIEF ENGINEER AND THE MANUFACTURER AS TO WHETHER THE FOLLOWING DEVICES SHOULD BE SPECIFIED

ONTROL

C.	Miscellaneous Control Devices.

1.	Provide hot gas by-pass valve, associated piping and wiring to permit operation below minimum step of loading

2.	Load limit thermostat: Unload compressor on excessively high temperature of chilled water return

3.	Low ambient control shall be accomplished with condenser dampers and controls. Operate to 0 degrees ambient temperature

NOTE: COORDINATE WITH ELECTRICAL DEPARTMENT.

4.	Provide unit mounted disconnect switch.

D.	Provide flow switch for chilled water to prevent compressor operation without adequate water flow

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS. OPTION 2 APPLIES TO CENTRIFUGAL CHILLERS ONLY, COMPRISING PARAGRAPHS 2.02 THROUGH 2.12 INCLUSIVE. REFER TO OPTION 1 FOR RECIPROCATING CHILLERS. INCLUDE ITEMS IDENTIFIED B *ONLY FOR PROJECTS WITH HEAT RECOVERY SYSTEM

7)	CHILLER UNIT

A.	Provide packaged outdoor chiller unit, factory assembled in accordance with ARI Standard 550. Unit shall be complete with compressor, compressor motor, evaporator, *heat recovery condenser, air cooled condenser, air cooled condenser fans, fan motors, weatherproof equipment enclosure and control panel, interconnecting refrigerant piping and fittings, automatic controls, safety cut-outs, electric starters, insulation and supported on a welded steel framework. Unit shall be factory prewired, tested and charged with refrigerant and oil

B.	Factory Insulation:

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. INCLUDE ITEMS IDENTIFIED BY * ONLY FOR PROJECTS WITH HEAT RECOVERY SYSTEMS

1.	Evaporator, *condenser, compressor, and piping insulation for chiller cold surfaces shall be in accordance with manufacturers' standards and Section INSULATION

a.	Condenser insulation shall be without vapor barrier

2.	Insulation finish, damage protection shall be per manufacturers' standards. Water boxes shall have removable insulated covers with vapor sealed joints

C.	The unit shall be similar to Trane Model CVAC.

8)	COMPRESSOR

A.	Provide serviceable, hermetically sealed compressor requiring no shaft seals. The compressor shall be centrifugal, of required stages. Maximum acceptable compressor power consumption shall be as shown on the drawings. Compressor impeller shall be constructed of nonferrous, cast aluminum or approved equivalent material dynamically and statically balanced after fabrication and tested to minimum 25 percent overspeed and sufficiently rigid to prevent any vibration at operating speeds. Operating speed below first critical speed. Maximum impeller speed shall be 13,000 rpm. Compressor casing shall be close-grain cast iron or approved equivalent material

B.	Provide forced-circulation lubricating system with:

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS:

UMP

1.	Motor-driven oil pump and motor starter.

2.	Main oil pump driven either by motor or through gears from compressor shaft

UMP

C.	Oil pump shall operate automatically before compressor start and during coast down. Oil flow must be proven for compressor to run. Provide oil system complete with: pressure-relief valves, oil piping, gauges, sight ports, thermometers, oil pressure switches, oil cooler designed for use with chilled water, condenser water or directly cooled by refrigerant, oil filter and oil reservoir

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY REFERENCES DIRECTLY AFFECTING WORK OF THIS SECTION. NOT REQUIRED IF SYSTEM IS DESIGNED TO PREVENT REFRIGERANT FROM CONTACTING OIL AND GUARANTEED NOT TO ABSORB OIL DURING PROLONGED SHUTDOWNS

D.	Oil heater shall be thermostatically controlled and sized to prevent oil from absorbing refrigerant during shutdowns

E.	Automatic capacity control: Provide variable inlet guide vanes operating through an arc of 90 deg. Vanes shall be constructed of stainless steel or nonferrous alloy with heat-treated stainless steel or nonferrous alloy shafts. Vanes shall have an approved-type positive seal where vane operating mechanism transmits motion to linkage

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS:

STAGE

F.	Multistage compressors: Flash gases shall be removed from liquid cooler at one or more intermediate stages

G.	Single-stage compressors shall have liquid subcooling in refrigerant condenser

STAGE

H.	Single stage compressors:

1.	Thrust bearing: L-10 life, 100,000 hours.

2.	Gas balance.

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY REFERENCES DIRECTLY AFFECTING WORK OF THIS SECTION

I.	Gear Drive: Provide self-aligning type with sufficient capacity to transmit maximum compressor load under all operating conditions and to operate without objectionable noise or vibration. Design and manufacture shall be in accordance with latest American Gear Manufacturers' Association (AGMA) standards. Provide double helical type gear with gear teeth flooded continuously with filtered oil. Provide pressure-lubricated bearings suitable for both gears and pinions. Temperature rise of gears shall not exceed 70 deg F above ambient temperature at full load

9)	EVAPORATOR

A.	Provide shell and tube type with a fouling factor of 0.0005.

B.	Shell shall be welded steel construction. Design water side for 150 psig working pressure and test not less than

1.	times design working pressure. Test refrigerant side at 285 psig

C.	Tubes shall be copper tubes with a minimum 0.028 inch wall thickness, 3/4 inch nominal diameter and with integral copper fins. Tubes shall be rolled into grooved holes in tube sheets and supports in equal sized holes for all tubes and shall be removable without affecting tube sheet or causing leakage of adjacent tubes. Supports shall be maximum 5 ft on center

D.	Carbon steel tube sheets shall be suitable for withstanding working pressure and welded to evaporator shell with intermediate tube sheets to prevent tube vibration

E.	Provide water boxes constructed of high-grade carbon steel, or material of equivalent strength, suitable for 150 psig working pressure

1.	Provide vent and drain connections connected to shell in manner to prevent shell exposure to water, tappings for thermometers, control bulbs and gauges

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS:

2.	Provide water nozzles for main piping connections with:

END

a.	Flanged end.

b.	Grooved end.

c.	Welding end.

END

F.	Provide baffles to prevent direct impingement of liquid on tubes and to uniformly distribute liquid refrigerant, nonferrous eliminators to prevent liquid refrigerant from entering compressor, refrigerant-charging connection. Provide sight glass to indicate liquid refrigerant level and thermometer well to indicate refrigerant temperature

G.	Relief valve: Provide rupture valve or disc suitable for connecting relief piping in accordance with requirements of authorities having jurisdiction and the Safety Code for Mechanical Refrigeration, ANSI, B-9.l

H.	Water velocity shall be maximum 10 ft per second in tubes.

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. DELETE THE FOLLOWING IF NOT REQUIRED IN THIS PROJECT AND RENUMBER THE FOLLOWING PARAGRAPHS

10)	HEAT RECOVERY CONDENSER:

A.	Provide shell and tube type with fouling factor of 0.0005 with construction, similar to chiller. Design water side for 150 psig working pressure, test not less than 1.5 times design working pressure, test refrigerant side at 413 psig. Heat recovery condenser shall be complete with tubes, tube sheets, intermediate tube sheet supports and water boxes

B.	Provide baffles to prevent direct impingement of refrigerant gases upon tubes and to uniformly distribute gas refrigerant over length of condenser

C.	Controls: Provide three way modulating valve in liquid refrigerant line to control flow of refrigerant in response to system heating water entering temperature. Provide complete modulation from l00 percent heat recovery to l00 percent air-cooled

11)	AIR COOLED CONDENSER

A.	Provide belt driven propellor type fans with permanently lubricated ball bearings, built-in thermal overload protection and belt drives selected in excess of 1.75 service factor

B.	Provide extended surface coils with seamless copper tubes, aluminum fins and factory tested at 375 psig under water

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. ALUMINUM FINS ARE STANDARD. IF THIS PROJECT JUSTIFIES THE USE OF COPPER, EDIT ACCORDINGLY

C.	Provide sub-cooling circuit, accumulator and low ambient temperature control

12)	COMPRESSOR MOTOR:

A.	Provide extra-heavy construction frame, guaranteed by compressor manufacturer to be suitable for support of impeller housings. Shaft shall be designed so that first critical speed is well above operating speed. Bearings shall be cartridge sleeve type supporting rotating assembly. Bearings shall be readily accessible for servicing. Motor shall be squirrel cage, suitable for star-delta starting and speed shall be 3600 rpm nominal

B.	Motors shall be chilled water cooled or refrigerant-cooled, suitable for hermetic operation, capable of withstanding on-off cycling at 20-minute intervals continuously without damage to motor and guaranteed by manufacturer for continuous load operation at maximum brake horsepower with centrifugal compressor

NOTE: COORDINATE WITH ELECTRICAL DEPARTMENT.

13)	MOTOR CONTROLLER:

A.	Provide NEMA Standard Magnetic type.

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS:

CONTR

1.	Provide closed-transition, star-delta type.

2.	Provide three magnetic overload relays with manual-reset, one per phase

3.	Provide definite time-limit acceleration and overload protection in each phase

CONTR

B.	Accessories, provide the following:

1.	Three position ammeter, switch and current transformer for reading current in each phase

2.	Ammeter and voltmeter mounted on compressor motor starter enclosure

3.	Phase reversal and phase failure protection.

4.	Under-voltage relay with reset pushbutton.

5.	Control voltage transformer.

6.	Elapsed time hour meter.

C.	Controllers shall be suitable for starting compressor motor intermittently at 20 minute intervals continuously without damage to controller

14)	CONTROL PANEL

A.	Provide panel complete with condenser pressure gauge, evaporator pressure gauge, lubricating oil pressure gauge and switch permitting manual or automatic operation of oil pump. Specified safety controls may be located on gauge board as approved

B.	Control panel shall be wired, assembled and adjusted at factory and mounted on compressor-evaporator assembly inside enclosure

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS:

THERM

C.	Provide 9 inch scale separable socket thermometer with brass case to indicate temperature of chiller liquid refrigerant and temperature of liquid refrigerant from condenser

D.	Provide thermometer wells for thermometers to indicate temperature of chiller liquid refrigerant and temperature of liquid refrigerant from condenser

NOTE: EDIT SEQUENCE OF OPERATION IN SECTION AUTOMATIC CONTROL SYSTEM TO CORRESPOND WITH THE FOLLOWING PARAGRAPH

THERM

15)	CONTROLS:

A.	Capacity control: Provide complete automatic capacity controls with starting and stopping and modulating capacity from 10 percent to 100 percent. Compressor shall be started unloaded with electric-pneumatic interlock and means to prevent excessive cycling of machine to prevent damage to motor or starter. Pneumatic or electric operator shall modulate compressor inlet guide vanes from 100 percent load to 10 percent load

B.	Safety controls with indicating pilot lights: Provide low refrigerant pressure or low temperature for water chiller, high refrigerant pressure, low compressor oil pressure, minimum chilled water flow, high motor temperature, high oil temperature and compressor motor current-limiting device to operate capacity-control mechanism with limit load on compressor motor to safe maximum at all times

C.	Safety controls operation: Provide fully automatic system with relays, piping, paddle-type flow switch in chilled water lines and other necessary appurtenances. Units shall not start without proper chilled water flow. Units shall be shut down upon reduction below predetermined water flow across chiller and with activation of other safety controls furnished with refrigeration machines

D.	Furnish complete instructions for installation of system including additional required accessories

16)	ENCLOSURES

A.	Equipment Room.

1.	Enclosures shall house all components except air-cooled condenser and starter and shall be insulated and constructed of galvanized steel and finished with vinyl paint

2.	Provide enclosures with lighting, 115 volt convenience outlet and key-locked door

NOTE: INCLUDE AS APPLICABLE FOR THIS PROJECT. DETERMINE IF EITHER OF THE FOLLOWING IS REQUIRED FOR THIS PROJECT. EDIT AS REQUIRED

EATER

a.	Provide electric unit heater(s) for freeze protection to -20 degrees ambient temperature

b.	Provide fan-coil unit for high ambient temperatures

EATER

B.	Starter Compartment: Provide NEMA 3 weatherproof enclosure with fully-opening doors with mechanical interlock to disconnect power when door is opened

Part 3 -	EXECUTION

1)	INSTALLATION

A.	Install units in accordance with manufacturer's instructions

B.	Provide main piping connections, flanged, within 12 inches of equipment to allow removal of headers and tubes without major removal of piping

C.	Unit and accessories' piping shall be in accordance with recommendations of manufacturer's recommendations

D.	Refer to Section PIPING.

E.	Mounting:

NOTE: SELECT APPLICABLE OPTION FROM THE FOLLOWING LISTINGS:

VIBRATION

1.	Roof curb or frame: Install on spring vibration isolators: Refer to Section VIBRATION ISOLATION. Isolation spring and steel base shall be on minimum 4 inches high concrete pad

NOTE: APPLICABLE WHEN NO "VIBRATION ISOLATION" SECTION EXISTS

2.	Units shall be guaranteed to prevent transmission of vibration to building. Provide spring isolators with 1 inch static deflection and seismically restrained. Correct objectionable vibration conditions at no cost to Owner and submit for review

VIBRATION

F.	Lubrication: Charge equipment with recommended oil. Provide 2 charts in glazed frames indicating type of oil for each location and maintenance schedule for each lubricated part

G.	Refrigerant charge: Provide equipment with complete refrigerant charge and a guaranteed charge for one year after system acceptance

2)	TESTS AND START-UP

A.	The following shall be supervised by unit manufacturer's representative

1.	Charging.

2.	Start-up.

3.	Field testing.

4.	Two days minimum, exclusive of instruction period.

B.	Dehydrating: Units shall be site tested for leaks and leaks shall be checked with halide testing device

1.	Units shall be dehydrated by producing vacuum to 100 microns with high vacuum pump. Vacuum shall be maintained for 4 hours and at the end of 4 hour period, the pump shall be stopped. Vacuum shall be maintained in refrigeration unit for 24 hours without losing more than 50 microns

2.	Certify tests and submit 6 copies before acceptance.

3)	OPERATING INSTRUCTIONS

A.	Provide services of competent instructor for period of two eight-hour days. Upon completion and acceptance of installation, properly acquaint authorized Owner's representatives with details as to enable them to obtain maximum efficiency in the plant operation

B.	Obtain written acceptance for each instruction day from Owner's representative