Engineering Specifications for PT2 Cooling Towers

Detailed PT2 Specification formatted for word processor use

1.0 Open Cooling Tower

1.1 General: Furnish and install ____factory assembled, induced draft counterflow, axial fan, open cooling tower(s) with vertical air discharge, conforming in all aspects to the specifications and schedules as shown on the plans. Overall dimensions shall not exceed approximately ____ft (m) long x ____ft (m) wide x ____ft (m) high. The total connected fan horsepower shall not exceed ____HP (kW). The cooling tower(s) shall be Baltimore Aircoil Company Model(s) ________________.

1.2 Thermal Capacity: The open cooling tower(s) shall be warranted by the manufacturer to cool ______USGPM (l/s) of water from ____°F (°C) to ____°F (°C) at ____°F (°C) entering wet-bulb temperature. The thermal performance shall be certified by the Cooling Technology Institute in accordance with CTI Certification Standard STD-201. Manufacturers' performance guarantees or performance bonds without CTI Certification or independent field thermal performance test shall not be accepted. The cooling tower(s) shall comply with the energy efficiency requirements of ASHRAE Standard 90.1.

1.3 Quality Assurance: The manufacturer shall have a Management System certified by an accredited registrar as complying with the requirements of ISO-9001 to ensure consistent quality of products and services. Manufacturers that are not ISO-9001 certified shall not be acceptable.

1.4 Warranty: Unless otherwise noted, the manufacturer's standard equipment warranty shall be for a period of not less than one year from date of startup or eighteen months from date of shipment, whichever occurs first. In addition, the manufacturer shall warrant the rotating mechanical equipment, including fans, fan motors, fan shafts, bearings, sheaves and associated supports for not less than five (5) years from date of shipment.

2.0 Construction Details

Casing

2.1 Corrosion Resistant Standard Construction: All steel panels and structural members shall be constructed of heavy-gauge G-235 (Z700 metric) hot-dip galvanized steel with all edges given a protective coating of zinc-rich compound.

(Alternate 2.1) Thermosetting hybrid polymer: All steel panels and structural members shall be protected with a thermosetting hybrid polymer for superior corrosion protection. G-235 (Z700 metric) hot-dip galvanized steel shall be prepared in a four-step (clean, pre-treat, rinse, dry) process with an electrostatically sprayed, thermosetting hybrid polymer fuse-bonded to the substrate during a thermally activated curing stage and monitored by a 23-step quality assurance program. Finish shall withstand 6000 hours of 5% salt spray test per ASTM B117 without blistering, chipping or loss of adhesion. Type 304 stainless steel shall be considered an acceptable alternative. Uncoated G-235 galvanized steel shall not be considered an acceptable alternative.

(Alternate 2.1) Corrosion Resistant Type 304 Construction: All steel panels and structural members shall be constructed of type 304 stainless steel and assembled with type 304 stainless steel nut and bolt fasteners.

Cold Water Basin

2.2 Cold Water Basin : The cold water basin shall be constructed of heavy-gauge G-235 (Z700 metric) hot-dip galvanized steel panels and structural members. Standard basin accessories shall include: a brass make-up valve with large diameter polystyrene filled plastic float for easy adjustment of the operating water level, removable anti-vortexing device to prevent air entrainment, and large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles.

Alternate 2.2) Cold Water Basin : The cold water basin shall be constructed of heavy-gauge type 304 stainless steel panels and structural members up to the heat transfer section/basin joint. All factory seams in the cold water basin shall be welded to ensure watertight assembly and welded seams shall be warranted against leaks for five (5) years. Standard basin accessories shall include: a brass make-up valve with large diameter polystyrene filled plastic float for easy adjustment of the operating water level, removable anti-vortexing device to prevent air entrainment, and large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles. A bolted type 304 stainless steel basin shall not be an acceptable alternative.

(Alternate 2.2) Cold Water Basin protected with TriArmor TM Corrosion Protection System: The cold water basin shall be protected with the TriArmor TM Corrosion Protection System. The system shall consist of G-235 galvanized steel encapsulated with a thermosetting hybrid polymer further protected by a polyurethane liner factory applied to all submerged surfaces. The polyurethane barrier shall seal all factory seams in the cold water basin to ensure a corrosion resistant and water tight construction, and shall be warranted against leaks and corrosion for five (5) years. Field applied polyurethane or polyurethane applied directly to galvanized steel is not an acceptable alternative. Standard basin accessories shall include: a brass make-up valve with large diameter polystyrene filled plastic float for easy adjustment of the operating water level, removable anti-vortexing device to prevent air entrainment, and large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles. The strainer and anti-vortexing device shall be constructed from type 304 stainless steel to prevent corrosion. A welded type 304 or 316 stainless steel basin shall be an acceptable alternative; provided the basin is warranted against leaks and corrosion for a period of at least 5 years. A bolted type 304 stainless steel basin shall not be an acceptable alternative.

EverTough

(Alternate 2.1 AND 2.2) TriArmor TM cold water basin with thermosetting hybrid polymer upper section: All steel panels and structural members shall be protected with a thermosetting hybrid polymer. Type 304 stainless steel casing and structural members are an acceptable alternative; G-235 galvanized is not acceptable. The cold water basin shall be protected with the TriArmor TM Corrosion Protection System. The system consists of G-235 galvanized steel encapsulated with a thermosetting hybrid polymer further protected by a polyurethane barrier applied to all submerged surfaces exposed to a circulating system water. The polyurethane barrier shall seal all factory seams in the cold water basin to ensure a corrosion resistant and water tight construction, and shall be warranted against leaks and corrosion for five (5) years. Standard basin accessories shall include: a brass make-up valve with large diameter polystyrene filled plastic float for easy adjustment of the operating water level, removable anti-vortexing device to prevent air entrainment, and large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles. The strainer and anti-vortexing device shall be constructed from type 304 stainless steel to prevent corrosion. A bolted type 304 basin shall not be an acceptable alternative.

2.3 Air Inlet Louver Screens: All louvers shall be constructed from PVC. Louver sections shall be individually removable in 12” wide (maximum) sections, allowing for quick and easy access to any part of the cold water basin without the need for tools. Louvers shall prevent debris from entering the cold water basin as well as preventing splashout. Louvers which are greater than 12” wide or require tools for removal shall not be an acceptable alternate.

2.4 Wind and Seismic Rating: The cooling tower shall be constructed of heavy-gauge steel utilizing double-brake flanges for maximum strength and rigidity and reliable sealing of watertight joints. The structure shall be designed, tested and certified in accordance with IBC 2006 regulations to meet a seismic load S DS = ___ g and a wind load of ___ psf. Units not provided with a certificate of IBC 2006 compliance shall not be an acceptable alternative.

2.5 Rigging: The cooling tower shall be designed and constructed to withstand rigging of the casing and cold water basin as a single piece.

2.6 Casing Field Joint: The heat transfer section shall be joined to the lower section without the use of a gasket or sealer. The field joint shall be self aligning and require a minimum number of fasteners.

2.7 Heat Transfer Section: The heat transfer section(s) shall consist of fill, spray water distribution system and drift eliminators arranged for optimal thermal performance with minimal drift.

2.8 Fill: The fill shall be formed from self-extinguishing polyvinyl chloride (PVC) having a flame spread rating of 5 per ASTM E84 and shall be impervious to rot, decay, and fungus or biological attack. The fill shall be suitable for use as a working platform, and shall be provided and performance tested by the cooling tower manufacturer to assure single source responsibility and control of the final product. The fill shall be able to withstand a water temperature of 140°F (60.0º C).

(Alternate 2.8) Fill: The fill shall be formed from self-extinguishing high temperature polyvinyl chloride (HPVC) having a flame spread rating of 5 per ASTM E84 and shall be impervious to rot, decay, and fungus or biological attack. The fill shall be provided and performance tested by the cooling tower manufacturer to assure single source responsibility and control of the final product. The fill shall be able to withstand a water temperature of 150°F (65.6º C).

2.9 Water Distribution System: Water shall be distributed evenly over the fill by a water distribution system consisting of a header and spray branches of Schedule 40 PVC pipe with large orifice, non-clog plastic distribution nozzles. The headers shall have a removable cap facilitating quick header cleanout without removal. The spray nozzles shall be held in place by snap-in rubber grommets and the branches should be removable without tools or removal of branch supports , allowing quick removal of individual nozzles or complete branches for cleaning or flushing. Branches that require tools for removal or removal of branch supports shall not be an acceptable alternative.

2.10 Drift Eliminators: Eliminators shall be constructed of specially formulated PVC and be removable in easily handled sections. They shall have a minimum of three changes in air direction.

3.0 Mechanical Equipment

3.1 Fan(s): Fan(s) shall be axial flow with aluminum alloy blades selected to provide optimum cooling tower thermal performance with minimal sound levels. Air shall discharge through a fan cylinder designed for streamlined air entry and minimum tip clearance for maximum fan efficiency. The top of the fan cylinder shall be equipped with a conical, non-sagging removable fan guard. The fan(s) and fan drive system, including the fan motor, shall be factory test-mounted and aligned to ensure reliable operation and ease of maintenance.

(Alternate 3.1) Fan(s): Fan(s) shall be low sound, axial flow with aluminum alloy blades selected to provide optimum cooling tower thermal performance with reduced sound levels. Air shall discharge through a fan cylinder designed for streamlined air entry and minimum tip clearance for maximum fan efficiency. The top of the fan cylinder shall be equipped with a conical, non-sagging removable fan guard. The fan(s) and fan drive system, including the fan motor, shall be factory test-mounted and aligned to ensure reliable operation and ease of maintenance.

3.2 Bearings: Fan(s) and shaft(s) shall be supported by heavy-duty, self-aligning, grease packed ball bearings with moisture proof seals and integral slinger collars, designed for L- 10 80k Life. Extended bearing lube lines shall be terminated at the access door for ease of maintenance, and shall require opening the access door to insure proper lubrication.

3.3 Fan Drive : The fan(s) shall be driven by a one-piece, multi-groove, solid back V-type powerband with taper lock sheaves designed for 150% of the motor nameplate horsepower. The powerband shall be constructed of neoprene reinforced polyester cord and be specifically designed for cooling tower service.

3.4 Sheaves: Fan and motor sheave(s) shall be fabricated from corrosion-resistant materials to minimize maintenance and ensure maximum drive and powerband operating life.

3.5 Fan Motor on models PT2-1009, PT2-1012 and PT2-1212: Fan motor(s) shall be totally enclosed air over (TEAO), reversible, squirrel cage, ball bearing type designed specifically for cooling tower service. The motor(s) shall be furnished with special moisture protection on winding, shafts, and bearings and appropriately labeled for “cooling tower duty.” Motor(s) shall be mounted on an interior, adjustable base which allows the motor to slide to the exterior of the unit for servicing. A mechanical equipment removal davit mounting channel shall be included as standard and integral to the casing design. Motor adjustments shall be made from the exterior of the unit; internally adjustable motor bases shall not be an acceptable alternative.

(Alternate 3.5) Fan Motor on models PT2-0709, PT2-0809 and PT2-0812: Fan motor(s) shall be totally enclosed fan cooled (TEFC), reversible, squirrel cage, ball bearing type designed specifically for cooling tower service. The motor(s) shall be furnished with special moisture protection on winding, shafts, and bearings and appropriately labeled for “cooling tower duty.” Motor(s) shall be mounted on an adjustable, removable base, exterior to the unit. A hinged protective cover shall protect the motor from the elements, and the motor shall be accessible without the use of tools. A mechanical equipment removal davit mounting channel shall be included and integral to the motor base design. The motor base shall be removable without upsetting the drive alignment. Motor adjustments shall be made from the exterior of the unit with the included tool; internally mounted motors or motor bases that are not removable shall not be an acceptable alternative.

(Alternate 3.5) Fan Motors on model PT2-0412: Fan motors shall be enclosed air over (TEAO), direct drive, reversible, squirrel cage, ball bearing type designed specifically for cooling tower service. The motors shall be furnished with special moisture protection on winding, shafts, and bearings and appropriately labeled for “cooling tower duty.”

(Alternate 3.5) Fan Motor: Fan motor(s) for inverter duty shall be either totally enclosed air over (TEAO) or totally enclosed fan cooled (TEFC), reversible, squirrel cage, ball bearing type designed specifically for cooling tower service. The motor(s) shall be furnished with special moisture protection on winding, shafts, and bearings and appropriately labeled for “cooling tower duty.” Fan motor(s) shall be inverter duty type designed per NEMA Standard MG1, Section IV Part 31, Section IV, and Part 31 suitable for _____ volt, ____ hertz, and ___ phase electrical service. Furnish _____ HP, ______ RPM motors.

3.6 Mechanical Equipment Warranty: The fan(s), fan shaft(s), bearings, mechanical equipment support and fan motor shall be warranted against defects in materials and workmanship for a period of five (5) years from date of shipment.

4.0 Access

4.1 Tower Access: Permanently mounted, i nward sliding access door s are provided for safe and easy access to the spray branch and fan drive system for routine maintenance. Removable access doors are not acceptable.

5.0 Sound

5.1 Sound Level: To maintain the quality of the local environment, the maximum sound pressure levels (dB) measured 50 ft from the cooling tower operating at full fan speed shall not exceed the sound levels detailed below.

6.0 Accessories

6.1 Basin Heater(s): The cooling tower cold water basin shall be provided with electric heater(s) to prevent freezing in low ambient conditions. The heater(s) shall be selected to maintain 40°F (4.4°C) basin water temperatures at _____° F ambient. The heater(s) shall be ______V/____phase/___Hz electric and shall be provided with low water cutout and thermostat.

(Alternate) 6.1 Basin Heaters: A steam coil shall be factory installed in the cooling tower depressed sump of the cold water basin to prevent freezing during cold water shutdown. The steam coil shall be capable of maintaining 40°F (4.4°C) basin water temperature at a –20°F (-29.9°C) ambient temperature given 5 psig (34Kpa) at the coil inlet connection.

6.2 Basin Water Level Control: The cooling tower manufacturer shall provide an electric water level control (EWLC) system. The system shall consist of water level sensing and control units in quantities and locations as indicated on the drawings. Each water level sensing and control unit shall consist of the following: NEMA 4 enclosure with gasketed access cover; solid state controls including all necessary relays and contacts to achieve the specified sequence of operation; stainless steel water level sensing electrodes with brass holder; Schedule 40 PVC standpipe assembly with vent holes, and all necessary stainless steel mounting hardware. Provide PVC union directly below the control enclosure to facilitate the removal and access of electrodes and control enclosure.

The number and position of water level sensing electrodes shall be provided to sense the following: high water level, low water level, high water alarm level, low water alarm, and heater safety cutout.

6.3 Vibration Cutout Switch: Provide mechanical local reset vibration switch. The mechanical vibration cut out switch will be guaranteed to trip at a point so as not to cause damage to the cooling tower. To ensure this, the trip point will be a frequency range of 0 to 3,600 RPM and a trip point of 0.2 to 2.0 g's.

(Alternate) 6.3 Vibration Cutout Switch: Provide electronic remote reset vibration switch with contact for BAS monitoring. Wiring shall be by the installing contractor. The electronic vibration cut out switch shall be set to trip at a point so as not to cause damage to the cooling tower. The trip point will be 0.45 in/sec (0.0114 m/sec).

6.4 Basin Sweeper Piping: The cold water basin of the cooling tower shall be equipped with PVC basin sweeper piping for a filter or separator (supplied by others).

6.5 Discharge Options: The unit shall be equipped with a tapered hood lined with sound absorbing fiberglass acoustical baffles to reduce sound levels from the top of the unit.

6.6 Water Silencers: The unit shall be equipped with PVC water silencers in the cold water basin to reduce falling water sound emissions.

6.7 Fill Inspection Panel: The unit shall be equipped with a removable access panel in the upper casing to easily inspect and remove the fill bundles. Contractor shall be responsible for installing an access panel if one is not provided from the manufacturer.

6.8 Mechanical Equipment Removal Davit: The unit shall be equipped with a mechanical equipment removal davit. The motor shall be lowered from the mechanical equipment supports down to grade. Davit shall attach to the unit without the need for tools. If tools are required for davit installation or removal, provide (1) davit for each motor provided.

7.0 Equipment Controls

7.1 Variable Frequency Drive(s) : A variable frequency drive (VFD) shall be provided for each fan motor. The supplier of the VFD shall be the manufacturer of the evaporative cooling equipment. The VFD shall have a 3-contactor bypass, 3% input line reactor, a removable keypad, an RS232 terminal for PC connection, and a circuit breaker disconnect. Fuse protection will not be accepted. Control voltage shall be 24V to minimize the size of the enclosure which should not exceed _____ ft x _____ ft x ____ ft and the weight should not exceed ____ lbs. VFD shall be provided in a NEMA (1)(3R)(12) enclosure. The VFD shall be compatible with a (ModBus) (LonWorks) (Johnson N2) Building Automation System.

OR

7.1 Enclosed Controls: An enclosed control panel shall be provided for each cell of the evaporative cooling equipment. The panel shall include full voltage, non-reversing (FVNR) fan motor and pump motor (if applicable) starters in a common enclosure. The panel shall be provided with a main circuit breaker disconnect and a separate circuit breaker for each motor or speed. Fuse protection will not be accepted. Panels containing basin heaters shall have an Earth Leakage Breaker containing ground fault protection. Starters above 25 A shall be NEMA rated. IEC starters will be accepted for motors below 25 A. Panel shall include a 120V/60Hz control power transformer, Hand-Off-Auto switches for each starter or contactor, and pilot lights for each component. Enclosed controls shall be provided in a NEMA (1)(3R)(4)(4X)(12) enclosure.

Optional enclosed control features: (A temperature sensor shall be provided with the enclosed controls.)(A temperature controller shall be provided with the enclosed controls.)(A basin heater contactor with circuit breaker shall be provided.)(A vibration cutout switch input shall be provided.)

7.2 Safety Switch(es): A heavy-duty, non-fusible safety disconnect switch shall be provided by the manufacturer of the evaporative cooling equipment. Switch shall be single-throw, 3-pole design, rated up to 600 VAC. Switch shall have triple padlocking capability, a visible double break rotary blade mechanism, a clearly visible On/Off handle, an interlocking mechanism to prevent door opening with handle in On position, and a clear line shield. Safety switch shall be provided in a NEMA (1)(3R)(12) enclosure.

7.3 Terminal Box (Not available on externally mounted motor models PT2-0709, 0809 and 0812): A heavy-duty externally mounted terminal box shall be provided by the manufacturer of the evaporative cooling equipment. All wiring for the fan motor(s) and vibration cutout switch(s) shall be pre-wired from the factory and terminated on the outside face of the BAC unit in a clearly marked terminal box. The terminal boxes shall be UL 1773 listed and CSA certified. The terminal boxes shall be provided with a standard five year warranty. The Terminal Box shall include a factory-mounted enclosure, factory wiring to terminal blocks for the fan motors and vibration cutout switches, and grounding lugs. Field mounted terminal boxes shall not be an acceptable alternative.