CT 3-4_Series VFL Cooling Tower O M.pdf

O p era tio n

M a in ten a n ce M a n u a ls Series V Closed Circuit Cooling Towers and Evaporative Condensers Table of Contents..............................................................Page Recommended Maintenance Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N73 Operation and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N73

Initial and Seasonal Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N73 Extended Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N74

Detailed Component Maintenance Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N75 Cold Water Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N75 Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N76 Fan Drive System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N76 Fan Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N77 Fan Shaft Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N77 Sleeve Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N78 Locking Collars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N78 Water Distribution System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N78 Water Level Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N79

Figure 1 - VFL Closed Circuit Cooling Tower and VCL Evaporative Condenser

Fan Shaft and Bearing

V-Belt Drive System with Guard

Fan Motor

Spray Nozzles Eliminators

Spray Branches

Coil

Access Door

Spray Pump

N71...because temperature matters™

S er ie s

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N72 Baltimore Aircoil Company

Casing

Coil Spray Nozzles

Spray Branches

Eliminators

Fan Housing

Fan Screens

Fan

Fan ShaftFan Bearing

Fan Drives

Fan Motor

Water Bleed Line

Spray Pump

Strainer

Adjustable Float

Water Make-up Valve Assembly

Figure 2a - Heat Transfer Coil Section for VF1 Closed Circuit Cooling Tower and VC1

Evaporative Condenser

Figure 2b - Basin Section for VF1 Closed Circuit Cooling Tower and

VC1 Evaporative Condenser era tio n

M a in ten a n ce M a n u a ls

N73...because temperature matters™

Table 1: Recommended Maintenance Services[1]

WARNING: Do not per form any service on or near the fans , motors, drive s, or inside the unit without fi rst ensuri ng that the fans and the pum ps are disc onnected and locked out .

NOTES:

1. Recommended service intervals are for typical installations. Different environmental conditions may dictate more frequent servicing.

2. When operating in ambient temperatures below freezing, the unit should be inspected more frequently.

Refer to “Cold Weather Operation” on Page N102 for more details.

3. Tension on new belts must be readjusted after the first 24 hours of operation and quarterly, thereafter.

Operation and Maintenance Initial and Seasonal Start-up

General

• If the unit is mounted on vibration isolators or isolation rails, refer to the vibration isolation manufacturerås guidelines before loading/unloading weight from the unit.

• Verify fan and spray pump motors are disconnected and locked out.

• Conduct external inspection of the equipment. Check for leaks, corrosion, and any structural damage.

• Inspect piping and connections.

Cleaning

• Drain the cold water basin with the strainers in place.

• Remove all dirt and debris from the fan guards.

• Clean all mechanical components, such as the fans and motors.

• Flush the cold water basin interior to remove any accumulated dirt and debris.

• Remove, clean, and replace the strainers.

Type Service Start-Up Monthly Quarterly Annually Shutdown

Inspe ct and clean as necessary :

Inspect general condition of the unit[2] and check unit for unusual noise or vibration

X X

Clean and flush basin X X X

Inspect spray nozzles X X X

Clean basin strainer X X X

Drain basin and piping X

Check and adjust water level in basin X X

Check operation of make-up valve X X

Check and adjust bleed rate X X

Inspect heat transfer section X X

Inspect protective finish X

Mechanic al equipme nt system:

Check belt condition X X

Adjust belt tension[3] X X

Lubricate fan shaft bearings X X X

Lubricate motor base adjusting nut X X X

Check drive alignment X

Check motor voltage and current X X

Check fan bearing locking collars X X

Check fan motors for proper rotation X

Check fans for rotation without obstruction X X ie s

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N74 Baltimore Aircoil Company

Inspecti on

WARNING: Do not per for m any serv ice on or near the fans, motors , drives, or ins ide the unit without firs t ensur ing that the fans and the pum ps are disconnec ted and locke d out.

• At seasonal start-up or after prolonged shutdown, check the motor insulation with an insulation tester prior to the motor start-up.

• Prior to the seasonal start-up, check and adjust the belt tension. At the initial start-up, the belt tension may not require adjustment as the drive will be properly tensioned at the factory prior to shipment.

• Start the fan motors and check for proper fan rotation.

• Run the fans in manual mode for several minutes to check for any unusual noise or vibrations.

• Check that the float operated make-up valve is operating freely.

WARNING: Check to ensur e the controls for the fan motor s are set to allow a maximum of 6 on-off cycles per hour.

Star t-up

WARNING: Do not per for m any service on or near the fans, motor s, and dri ves, or insi de the unit wi thout first ensuring that the fans and the pumps are disconnect ed and loc ked out.

• Prior to seasonal start-up, lubricate the motor base adjusting screws (see Figure 6 on Page N77) and the fan shaft bearings. At initial start-up, no bearing lubrication is required since the bearings are factory lubricated prior to shipment.

• Fill the cold water basin with fresh water to the overflow level via the make-up valve.

o Water treatment for new installations: Initiate the biocide water treatment program at this time. Refer to

“Biological Control” on Page N106 for more details.

o Water treatment for seasonal start-up or after a shutdown period in excess of 3 days: Resume the biocide treatment program and administer a shock treatment of appropriate biocides prior to operating the fans. This will eliminate accumulated biological contaminants. Refer to “Biological Control” on Page N106 for more details.

• Set the make-up valve float so the water shuts off at the overflow level.

• Start the spray pump. See “Water Distribution System” on Page N78 for more details.

• Open the valve in the unit bleed line, and adjust the bleed by closing or opening the valve.

• Once the unit is operating, check the current and voltage of all three phases (legs) of the fan motors with a heat load on the unit under warm ambient conditions. The current must not exceed the nameplate ratings.

• Check the operation of the optional vibration cutout switch.

After 24 hours of operation under thermal load, perform the following serv ices:

• Check the unit for any unusual noise or vibrations.

• Check the operating water level in the cold water basin.

• Adjust make-up valve if necessary.

• Check the belt tension and readjust if necessary.

Extended Shutdown

WARNING: Do not per for m any serv ice on or near the fans, motors , and drives , or inside the unit wi thout fi rst ensur ing that the fans and the pumps are disconne cted and lock ed out.

Perform the fol lowin g services whenever the unit is shutdown in exces s of 3 days:

• If the unit is mounted on vibration isolators or isolation rails, refer to the manufacturerås guidelines before loading/unloading weight from the unit.

• Drain the cold water basin and all the piping (excluding the coils) that will be exposed to freezing temperatures. Heat trace and insulate all exposed piping.

Figure 3 - Water Make-up Valve Assembly era tio n

M a in ten a n ce M a n u a ls

N75...because temperature matters™

• Clean all debris, such as leaves and dirt, from the interior and exterior of the unit.

• Clean and flush the cold water basin with the basin strainers in place.

• Leave the cold water basin drain open so rain and melting snow will drain from the unit.

• Clean the basin strainer and re-install.

• Lubricate the fan shaft bearings, motor base, and motor base adjusting screw.

• Close the shut off valve in the make-up water line (supplied by others), and drain all exposed make-up water piping. Heat trace and insulate all exposed piping.

• Inspect the protective finish on the unit. Clean and refinish as required. Refer to “Corrosion Protection” on

Page N104 for more details.

• Secure the fan motors starting device(s) in the “OFF” position to ensure personal safety in case of future inspection or service.

Detailed Component Maintenance Procedures Cold Water Basin The fluid to be cooled is circulated inside the tubes of the unit's heat exchanger. Heat flows from the process fluid through the coil to the spray water outside which is cascading over the tubes. The spray water collects in the cold water basin, passes through the suction strainer and is pumped back to the distribution system. The cold water basin is constructed from one of the following materials of construction:

• Galvanized steel

• Thermosetting Hybrid Polymer

• Type 304 stainless steel

Water Levels

Table 2: Cold Water Basin Water Levels

• The make-up valve controls the operating level, which is maintained at the levels shown in Table 2.

• The operating water level in the cold water basin will vary with system thermal load (evaporation rate), the bleed rate employed, and the make-up water supply pressure.

• Check the operating water level monthly, and readjust the float when necessary to maintain the recommended operating level.

Inspect ion and Maint enance

WARNING: Openings and/or submerged obs tructions may exist in the bottom of the cold water basin.

Use caut ion when walking inside this equipment.

• Inspect the cold water basin regularly. Remove trash or debris accumulated in the basin or on the strainer.

• Quarterly, or more often if necessary, drain, clean, and flush the entire cold water basin with fresh water.

This will remove the silt and sediment, which normally collects in the basin during operation. If not removed, sediment can become corrosive and cause deterioration of the protective finish of metallic basins.

• When flushing the basin, leave the strainers in place to prevent the sediment from re-entering the system.

Model Number At Overflow Level (in.) At Operating Level (in.)

VFL,VCL 10” 5-1/2”

VF1-009 thru VF1-036, VC1-10 thru 135 18-1/2” 13-3/8”

VF1-048, VC1-150 thru 205 21-1/2” 16-5/8”

VF1-072, VC1-N208 thru N230 31” 17”

VF1-096, VF1-144N, VF1-192, VF1-288N,

VC1-N243 thru N470, VC1-C216 thru C469

31” 17”

VF1-1012, VF1-1018, VF1-1024, VF1-1036 24” 18”

VF1-144, VF1-216, VF1-288, VF1-432,

VC1-386 thru 1608

24-1/2” 14” ie s

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N76 Baltimore Aircoil Company

• Remove the strainers after the basin has been flushed.

• Clean and replace the strainers before refilling the basin with fresh water.

• Adjust the float to maintain the design operating level. See Table 2: “Cold Water Basin Water Levels”.

Fan Series V Closed Circuit Cooling Towers and Evaporative Condensers use centrifugal fans. Thoroughly inspect the fans for damaged or deteriorated fan blades and replace the fan as required.

Inspecti on and Maint enance

• If the unit is already in operation, while the fans are still running, check for any unusual noise or vibration.

• With the fans off and the motor locked out and tagged, check the general condition of the fans:

o Inspect for any loose or missing bolts in the locking collar and fan shaft bearings.

• Rotati on : Turn the fan shaft by hand to ensure that the shaft moves freely with no rough spots, binding or other malfunctions that could cause vibration or fan motor overload.

• Direction of Rotation: On initial start-up, or if the fan motor has been rewired, bump the fan motor and note the direction of rotation.

• Operation : On initial start-up, run the fan in the manual position for several minutes and check for any unusual noises or vibration.

Fan Drive System

Inspecti on and Maint enance

• These drives require a periodic check of the belt condition and, when necessary, tension adjustment. The recommended service intervals are as follows:

o Initia l Start-up : Servicing is not required prior to initial unit start-up. The drive has been tensioned and aligned at the factory.

o Seasonal Star t-up : Readjust the belt tension.

o Operat ion : After the first 24 hours of operation, readjust the belt tension on a new unit start-up or installation of a new belt. Thereafter, check the belt condition monthly, and adjust tension as necessary. Readjust tension at least once every 3 months.

• Belt tension check:

o Place a straight edge along the belt from sheave to sheave as shown in Figure 4a, or use a tape measure as shown in Figure 4b, to measure belt deflection.

o Apply a moderate force by hand (approximately 15 lbs/6.8 kg) evenly across the width of the belt in the center of the span between the sheaves.

o There is adequate belt tension if the belt deflects between 1/4” and 3/8” as shown in Figures 4a and 4b.

DRIVEN SHEAVEDRIVEN SHEAVE

BELTBELT

DRIVER SHEAVEDRIVER SHEAVE

STRAIGHT EDGESTRAIGHT EDGE

1/4” TO 3/8” DEFLECTION = PROPER BELTTENSION 3/8” DEFLECTION = PROPER BELT TENSION

D DRIVEN SHEAVEDRIVEN SHEAVE

BELTBELT

DRIVER SHEAVEDRIVER SHEAVE

TAPE MEASURETAPE MEASURE

1/4” TO 3/8” DEFLECTION = PROPER BELTTENSION3/8” DEFLECTION = PROPER BELT TENSION

Figure 4a Figure 4b era tio n

M a in ten a n ce M a n u a ls

N77...because temperature matters™

• Belt tension adjustment (if required):

o Loosen the lock nut on the motor base adjusting screw.

o Turn the motor base adjusting screw clockwise to tension the belt, or counterclockwise to relieve belt tension. During adjustment of belt tension, rotate the drives several times by hand to evenly distribute the tension throughout the belt.

• When the belt is properly tensioned, retighten the lock nut on the motor base adjusting screw.

NOTE: There should be no “chirp” or “squeal” when the fan motor is started.

Alignm ent:

• Check the drive alignment annually to ensure maximum belt life.

• Drive alignment check and adjustment:

• Place a straight edge across the driver and the driven sheaves as shown in Figure 5.

• The straight edge should contact all four points as shown in Figure 5 indicating proper drive alignment.

• There should be no more than 1/16” deviation from four points of contact.

• In case of realignment, loosen the motor sheave and align it with the fan sheave. Allow 1/4” for draw-up as the bushing screw is retightened.

Fan Motors Series V Closed Circuit Cooling Towers and Evaporative Condensers use cooling tower duty, premium efficient, totally enclosed, single-speed, single-winding, reversible ball bearing type motor(s).

Inspection and Maintenance

• Clean the outside of the motor at least quarterly to ensure proper motor cooling.

• After prolonged shutdowns, check the motor insulation with an insulation tester prior to restarting the motor.

Adju stable Motor Base Coat the motor base slides and adjusting screws (see Figure 6) every 3 months using good quality corrosion inhibiting grease such as one recommended for lubricating the fan shaft bearings.

Fan Shaft Bearings The fan shafts are supported by ball bearings (see Figure 7). Each bearing is equipped with a lubrication fitting and locking collar.

Ball Bearings Under normal operating conditions, the bearings should be greased every 2,000 operating hours or at least quarterly. The bearings should also be greased at seasonal start-up and shutdown. Only lubricate the bearings wi th one of the following water resistant inhibited greases which are good for ambient

Figure 7 - Ball BearingFigure 6 - Adjustable Motor Base

Points of Contact

Standard Driver Sheave

1/16”

MAX

1/16”

MAX

1/16”

MAX

Standard Driven Sheave

Figure 5 - Standard Drive Alignment ie s

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N78 Baltimore Aircoil Company temperatures ranging from -65°F (-53.9°C) to 250°F (121.1°C):

Only lubric ate the bear ings with a hand grease gun. Do not use high pres sure grease guns sinc e they may ruptur e the bear ing seals . When lubricating, purge the old grease from the bearing by gradually adding grease until a bead of new grease appears at the seal.

Sleeve Bearings Prior to start-up and during the first week of operation, the bearing oil cup (see Figure 8) must be refilled with an industrial-type mineral oil (see Table 3) to saturate the felt wick in the bearing reservoir. After the initial start-up, fill the bearing oil cup every 1,000 operating hours or at least every six months. When ambient temperatures below 0˚F are expected, a light oil must be used. With such light oils, the bearing oil cup should be checked and refilled several times during the first several hours of operation until the bearings reach operating temperature.

Table 3: Sleeve Bearing Lubricants

Caut ion: Do not use oi ls contai ning detergent s for bearing lubri cat ion.

Detergent oi ls will remov e the graphit e in the bearing sleeve and cause bearing failur e.

Also, do not disturb bearin g alignment by tightening the bearing cap adjustm ent on a new unit as it is adjusted at the factory.

Locking Collars Each eccentric lock ing collar should be chec ked quar terly to ensure that the inner bearing race is secured to the fan shaf t. The locking collar can be set using the following procedure (see Figure 9):

• Loosen the set screw.

• Using a drift pin or center punch, tap the collar (in the hole provided) tangentially in the direction of rotation while holding the shaft.

• Retighten the set screw.

Amoco - Rycon Premium #3 Exxon - Polyrex® EM Shell - Alvania #3 Chevron - SRI Exxon - Unirex N™ Shell - Dolium “R” Citgo - Polyurea MP2™ MobilGrease® - AW2 SKF - LGHP2™ Conoco - Polyurea 2™ Shell - Alvania RL3™ Unocal 76 - Unilife Grease™

Figure 9 - Locking Collar Assembly

Direction of Rotation

Figure 10 - Nozzle Spray Pattern

Figure 8 - Sleeve Bearing

Temp Ambient BAC P/N Texaco EXXON

70˚F to 100˚F 30˚F to 70˚F

582628PI

Regal R & O 320 Regal R & O 150

Teresstic 220 Teresstic 100

5˚F to 30˚F -25˚F to 5˚F

582627PI

Regal R & O 32 Capella 32

Teresstic 32 era tio n

M a in ten a n ce M a n u a ls

N79...because temperature matters™

• Inspect the coil surface. Any corrosion, damage, or obstructions must be corrected.

• Some VF1, VFL, VC1, and VCL units are provided with an extended surface finned coil. During the winter season, when the ambient temperature is well below design, units can operate with the spray pump off.

The coil is designed for seasonal dry operation followed by seasonal wet operation, and not for frequent cycling of the spray pump. Frequent spray pump cycling may lead to excessive scale buildup.

Cautio n: Don't use steam or high press ure water to clean PVC eliminators or materia ls othe r than steel.

Water Level Control There are two types of water level controls used on BAC units:

• Mechanical make-up valve assembly

• Optional electric water level control package

The unit water make-up valve assembly is located within easy reach from the access door at the connection end of the unit.

Mechanical Make-up Valve Assem bly A float-operated mechanical water make-up assembly is furnished as standard equipment on the unit. The standard make-up assembly consists of a corrosion resistant make-up valve connected to a float arm assembly actuated by a polystyrene-filled plastic float. The float is mounted on an all-thread rod held in place by wing nuts. The cold water basin operating water level can be adjusted by repositioning the float and all-thread rod using the wing nuts provided.

NOTE: If the unit has been ordered with the optional electric water level control package or is intended for remote sump application, a mechanical water make-up valve will not be provided.

Inspection and Maintena nce:

• Inspect the make-up valve assembly monthly and adjust if necessary.

• Inspect the valve annually for leakage. Replace the valve seat if necessary.

• Maintain the make-up water supply pressure between 15 psig and 50 psig for proper operation. BAC recommends a surge protector (provided by others) for pressures over 50 psig.

• Set the initial basin water level by adjusting the wing nuts, so that the make-up valve is completely closed when the water level in the cold water basin is at the overflow connection.

• With the design thermal load and the average water pressure (15 to 50 psig) at the valve, the above setting will produce operating water levels as stated in Table 2 on Page N75.

• If the thermal load is less than the design load at the time of unit start-up, the procedure may produce operating levels greater than those shown in Table 2. If operating levels are higher than specified, readjust the float in order to attain the recommended operating level.

• Closely monitor the water level in the cold water basin and adjust the level if necessary during the first 24 hours of operation.

• Operating at the recommended water level will ensure that the unit basin contains sufficient water volume to prevent air entrainment in the circulating spray pump during system start-up.

Opt ional Elect ric Water Level Contro l Package As an option, an electric water level control package is available in lieu of the mechanical make-up assembly.

The package consists of a probe-type liquid level control assembly and a slow-closing solenoid valve.

Stainless steel electrodes, factory-set at predetermined lengths, extend from an electrode holder into the cold water basin.

Inspection and Maintena nce:

• Clean the stainless steel electrodes periodically to prevent accumulations of scale, corrosion, sludge or biological growth, which could interfere with the electrical circuit.

• The water level is maintained at the recommended operating level regardless of the system thermal load.

Therefore, it is not recommended that the operating level be adjusted.

• During the start-up of units equipped with the electric water level control package, by-pass the control unit in order to fill the unit to the overflow connection.

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N80 Baltimore Aircoil Company

RReeccoommmmeennddeedd SSppaarree PPaarrttss BAC parts are the “Perfect Fit” for your cooling tower. These parts are specifically designed, engineered and manufactured to work in a cooling tower environment. They are the right parts, at competitive pricing levels, and BAC offers the best deliveries in the industry.

BAC stocks most common repair and retrofit parts in our Parts DepotSM and can ship other parts, often overnight, from any of our three manufacturing facilities strategically located in California, Delaware, and Illinois. In addition, most BAC Representatives maintain a local inventory of commonly used parts.

Even with this fast delivery capability, it is still recommended that certain essential, emergency repair parts be maintained in your local inventory, to minimize any potential downtime.

Basic Recommended Spare Parts Bearing set Float valve or repair kit Float ball Solenoid valve (if unit is equipped with electric water level control) Powerband or set of belts Spray nozzle kit with grommets Basin heater and low water cut out Door gasket Strainer (inlet and suction) Fan and sheave bushings Pump seal and gasket kit for coil products Automatic bearing greaser refill kit

Parts to Consider if Extended Downtime is a Concern Spray pump for coil products Fan or fan wheel Fan shaft Sheave set Fan motor