236500 Cooling Tower Specifications.pdf

NO: 22585 HARDIN COUNTY JUSTICE CENTER 10-3-22

HARDIN COUNTY JUSTICE CENTER FLUID COOLER INSTALLATION

ELIZABETHTOWN, KENTUCKY

COOLING TOWERS 236500 - 1

SECTION 236500 - COOLING TOWERS

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Closed-circuit, cooling tower.

2. Cooling tower control panels.

1.2 SUBMITTALS

A. Product Data: For product indicated. Include rated capacities, pressure drop, fan performance data, rating curves with selected points indicated, furnished specialties, and accessories.

B. Shop Drawings: Complete set of manufacturer's prints of cooling tower assemblies, control panels, sections and elevations, and unit isolation.

C. Startup service reports.

D. Operation and maintenance data.

E. Warranty.

1.3 QUALITY ASSURANCE

A. Electrical Components, Devices, and Accessories: Listed and labeled as defined in NFPA 70 latest issue, by a qualified testing agency, and marked for intended location and application.

B. ASHRAE/IESNA 90.1 for energy efficiency.

C. ASME Compliance: Fabricate and label heat-exchanger coils to comply with ASME Boiler and

Pressure Vessel Code: Section VIII, Division 1.

D. CTI Certification: Cooling tower thermal performance according to CTI STD 201, "Certification Standard for Commercial Water-Cooling Towers Thermal Performance."

1.4 WARRANTY

A. Special Warranty: Manufacturer's standard form in which manufacturer agrees to repair or replace the following components of cooling towers that fail in materials or workmanship within specified warranty period:

1. Fan assembly including fan, drive, and motor.

2. All components of cooling tower.

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3. Warranty Period: As specified on Equipment Schedule.

PART 2 - PRODUCTS

2.1 CLOSED-CIRCUIT, COOLING TOWERS

A. Products: Subject to compliance with the requirements, provide a cooling tower as manufactured by one of the following:

1. Baltimore Air Coil.

2. Evapco Inc.

3. Marley.

4. Approved equal.

B. Cooling tower designed to resist wind load of 30 lbf/sq. ft.

C. Wetted Parts

1. All wetted parts shall be manufactured of stainless-steel construction. Refer to

Equipment Schedule for grade of stainless steel required.

D. Casing and Frame:

1. Casing and Frame Material: Galvanized steel, ASTM A 653/A 653M, G235 coating.

2. Fasteners: Stainless steel.

3. Joints and Seams: Sealed watertight.

4. Welded Connections: Continuous and watertight.

E. Collection Basin:

1. Material: Stainless steel.

2. Strainer: Removable stainless-steel strainer with openings smaller than nozzle orifices.

3. Overflow and drain connections.

4. Makeup water connection.

F. Electric/Electronic, Collection Basin Water-Level Controller with Solenoid Valve:

1. Enclosure: NEMA 250, Type 4.

2. Sensors: Solid-state, multiple electrode probes and relays to control water makeup, low-and high-level alarms, and output for shutoff of pump on low level.

3. Electrode Probes: Stainless steel.

4. Water Stilling Chamber: PVC pipe.

5. Solenoid Valve: Slow closing, controlled and powered through level controller in response to water-level set point.

6. Electrical Connection Requirements: 120 V, single phase, 60 Hz.

G. Electric Basin Heater:

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1. Stainless-Steel Electric Immersion Heaters: Installed in a threaded coupling on the side of the collection basin.

2. Heater Control Panel: Mounted within cooling tower control panel.

3. Magnetic contactors controlled by a temperature sensor/controller to maintain collection basin water-temperature set point. Water-level probe shall monitor cooling tower water level and de-energize the heater when the water reaches low-level set point.

4. Control-circuit transformer with primary and secondary side fuses.

5. Terminal blocks with numbered and color-coded wiring to match wiring diagram.

6. Single-point, field-power connection to a non-fused disconnect switch and heater branch circuiting complying with NFPA 70.

7. Factory Wiring Method: Metal raceway for factory-installed wiring outside of enclosures, except make connections to each electric basin heater with liquid-tight conduit.

H. Water Distribution Piping: Main header and lateral branch piping designed for even distribution over fill throughout the flow range without the need for balancing valves and for connecting individual, removable, non-clogging spray nozzles.

1. Pipe Material: PVC.

2. Spray Nozzle Material: Plastic.

3. Piping Supports: Corrosion-resistant hangers and supports designed to resist movement during operation and shipment.

I. Recirculation Piping: PVC.

J. Spray Pump: Close-coupled, end-suction, single-stage, bronze-fitted centrifugal pump; with suction strainer and flow balancing valve, and mechanical seal suitable for outdoor service.

1. General Requirements for Spray Pump Motor: Comply with NEMA designation and temperature-rating requirements.

2. Motor Enclosure: Totally enclosed fan cooled (TEFC).

3. Energy Efficiency: Comply with ASHRAE/IESNA 90.1.

4. Service Factor: 1.15.

K. Heat-Exchanger Coils:

1. Tube and Tube Sheet Materials: Prime-coated steel tube and sheet with outer surface of tube and sheet hot-dip galvanized after fabrication.

2. Heat-Exchanger Arrangement: Serpentine tubes; and sloped for complete drainage of fluid by gravity.

3. ASME Compliance: Designed, manufactured, and tested according to ASME Boiler and

Pressure Vessel Code: Section VIII, Division 1, and bearing ASME "U" stamp; and sloped for complete drainage of fluid by gravity.

4. Field Piping Connections: Vent, supply, and return suitable for mating to ASME B16.5, Class 150 flange.

L. Drift Eliminator:

1. Material: FRP or PVC; with maximum flame-spread index of 25 according to

ASTM E 84.

2. UV Treatment: Inhibitors to protect against damage caused by UV radiation.

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3. Configuration: Multi-pass, designed and tested to reduce water carryover to achieve performance indicated.

M. Air-Intake Screens: Galvanized-steel wire mesh.

N. Belt Drive:

1. Belt-Drive Service Factor: 1.5 based on motor nameplate horsepower.

2. Sheaves: Fan and motor shafts shall have taper-lock sheaves fabricated from corrosion-resistant materials.

3. Belt: Multiple V-belt design with a matched set of belts.

4. Belt Material: Oil resistant, non-static conducting, and constructed of neoprene polyester cord.

5. Belt-Drive Guard: Comply with OSHA regulations.

O. Fan Motor:

1. General Requirements for Fan Motors: Comply with NEMA designation and temperature-rating requirements.

2. Motor Enclosure: Totally enclosed fan cooled (TEFC).

3. Energy Efficiency: Comply with ASHRAE/IESNA 90.1.

4. Service Factor: 1.15.

5. Insulation: Class F.

6. Variable-Speed Motors: Inverter-duty rated per NEMA MG-1, Section IV, "Performance

Standard Applying to All Machines," Part 31, "Definite-Purpose, Inverter-Fed, Polyphase

Motors."

7. Severe-duty rating with the following features:

a. Rotor and stator protected with corrosion-inhibiting epoxy resin.

b. Double-shielded, vacuum-degassed bearings lubricated with premium moisture-resistant grease suitable for temperatures between minus 20 and plus 300 deg F.

c. Internal heater automatically energized when motor is de-energized.

8. Motor Base: Adjustable, or other suitable provision for adjusting belt tension.

9. Number of Motors: two (2) minimum. Each fan shall be provided with independent motors and drives for redundancy operation.

P. Discharge Hoods:

1. Hood Configuration: Tapered; totally surrounding drift eliminators and constructed of same material as casing; and having factory-installed access doors.

Q. Vibration Switch: For each fan drive.

1. Enclosure: NEMA 250, Type 4.

2. Vibration Detection: Sensor with a field-adjustable acceleration sensitivity set point in a range of 0 to 1 g and frequency range of 0 to 3000 cycles per minute. Cooling tower manufacturer shall recommend switch set point for proper operation and protection.

3. Provide switch with manual-reset button for hardwired connection to fan motor electrical circuit.

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4. Switch shall, on sensing excessive vibration, shut down the fan.

R. Control Package: Assembled and wired, and functionally tested at factory before shipment.

1. Control panel and all components shall be listed and certified by a Nationally Recognized

Testing Laboratory (NRTL) in accordance with NFPA 70 – National Electrical Code – latest edition.

2. NEMA 250, Type 3R enclosure with removable internally mounted back plate.

Enclosure shall be lockable and vandal resistant

3. Control-circuit transformer with primary and secondary side fuses.

4. Terminal blocks with numbered and color-coded wiring to match wiring diagram. Spare wiring terminal block for connection to external controls or equipment.

5. Microprocessor-based controller for automatic control of fan and spray pump based on cooling tower leaving-water temperature with control features to improve operating efficiency based on outdoor ambient wet-bulb temperature by using adaptive logic.

6. Collection basin, electric/electronic level controller complying with requirements in

"Electric/Electronic, Collection Basin Water-Level Controller with Solenoid Valve"

Paragraph.

7. Electric basin heaters with temperature control and low-water-level safety switch for each cell, complying with requirements in "Electric Basin Heater" Paragraph.

8. Vibration switch for each fan, complying with requirement in "Vibration Switch"

Paragraph.

9. Single-point, field-power connection to a non-fused disconnect switch.

a. Branch power circuit to each motor and electric basin heater and to controls with a disconnect switch or circuit breaker.

b. NEMA-rated motor controllers, hand-off-auto switches, and overcurrent protection for each motor. Provide variable frequency controllers with manual bypass and line reactors for each variable-speed motor indicated.

c. Powered 115V/1 20-amp duplex convenience outlet in weather-proof service at

3R enclosure.

d. Branch power circuit for water treatment system submersible pump (115 V/1

Phase 20 amp). Circuit shall be interlocked and operate with spray pump operation.

e. Provide transformers as required for convenience outlet and heat trace power.

f. Provide 1P30A, 120V/1ph, GFCI, switch rated circuit breaker within the control panel for hardwired connection of temperature maintenance cabling (heat trace) and controls. Use of heat trace with cord and plug is not acceptable. Temperature

Maintenance Cabling and its associated controls shall be provided by the Fluid

Cooler Manufacturer

10. Factory-installed wiring outside of enclosures shall be in metal raceway, except make connections to each motor and electric basin heater with liquid tight conduit.

11. Visual indication of status and alarm with momentary test push button for each motor.

12. Audible alarm and silence switch.

13. Visual indication of elapsed run time, graduated in hours for each motor.

14. Cooling tower shall have hardware to enable BMS to remotely monitor, control and display at minimum the following:

a. Operational status of each motor.

b. Position of dampers.

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COOLING TOWERS 236500 - 6

c. Cooling tower entering and leaving-fluid temperature.

d. Fan vibration alarm.

e. Collection basin high- and low-water-level alarms.

f. Other points as specified in Section 230933 “Sequence of Operations for HVAC

Controls”.

S. Personnel Access Components:

1. Doors: Large enough for personnel to access cooling tower internal components from cooling tower end walls. Doors shall be operable from both sides of the door. Doors shall be lockable.

2. Internal Platforms: Aluminum, FRP, or galvanized-steel bar grating.

a. Spanning the collection basin from one end of cooling tower to the other and positioned to form a path between the access doors. Platform shall be elevated so that all parts are above the high-water level of the collection basin.

T. Capacities and Characteristics, as specified on Equipment Schedule.

2.2 SOURCE QUALITY CONTROL

A. Verification of Performance: Test and certify cooling tower performance according to

CTI STD 201, "Certification Standard for Commercial Water-Cooling Towers Thermal

Performance."

B. Factory pressure test heat exchangers after fabrication and prove to be free of leaks.

PART 3 - EXECUTION

3.1 STARTUP SERVICE

A. Engage a factory-authorized service representative to perform startup service.

B. Inspect field-assembled components, equipment installation, and piping and electrical connections for proper assemblies, installations, and connections.

C. Obtain performance data from manufacturer.

1. Complete installation and startup checks according to manufacturer's written instructions and perform the following:

a. Clean entire unit including basins.

b. Verify that accessories are properly installed.

c. Verify clearances for airflow and for cooling tower servicing.

d. Lubricate bearings.

e. Verify fan rotation for correct direction and for vibration or binding and correct problems.

f. Adjust belts to proper alignment and tension.

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g. Verify proper oil level in gear-drive housing. Fill with oil to proper level.

h. Check vibration switch setting. Verify operation.

i. Verify water level in tower basin. Fill to proper startup level. Check makeup water-level control and valve.

j. Verify operation of basin heater and control.

k. Replace defective and malfunctioning units.

D. Start-up of cooling tower and associated water pumps shall be performed by Manufacturer’s

Representative. Installing Contractor start-up is NOT acceptable.

E. Prepare a written startup report that records the results of tests and inspections.

END OF SECTION 236500